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89 vulnerabilities found for XenServer by Cloud Software Group
MOKSHA-2026-0021
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Cross-VM Traffic Sniffing via VIF.other_config Promiscuous Mode
Summary
A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can enable promiscuous mode on a VIF bridge port by setting VIF.other_config:promiscuous to true. The VIF hotplug script writes to /sys/class/net/vifX.Y/brport/promisc, causing the guest VM to receive all frames on the Linux bridge including traffic destined for other VMs. This enables cross-VM traffic sniffing in multi-tenant environments using Linux bridge networking. The key has no per-key RBAC protection and the attack requires a single API call.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can enable promiscuous mode on a VIF bridge port by setting VIF.other_config:promiscuous to true. The VIF hotplug script writes to /sys/class/net/vifX.Y/brport/promisc, causing the guest VM to receive all frames on the Linux bridge including traffic destined for other VMs. This enables cross-VM traffic sniffing in multi-tenant environments using Linux bridge networking. The key has no per-key RBAC protection and the attack requires a single API call."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0021"
}
],
"title": "Cross-VM Traffic Sniffing via VIF.other_config Promiscuous Mode"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0021"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0021",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0060
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Arbitrary Integer Passthrough to ionice via VBD.qos_algorithm_params
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can pass arbitrary integer values to the Linux ionice binary via the class key in VBD.qos_algorithm_params. The qos_class parser at xapi_xenops.ml:595-600 accepts any integer via Other(int_of_string s), and Ionice.to_class_param passes Other x directly as the -n argument. No range validation is performed - valid range is 0-7 but negative and extreme values are accepted. Kernel behavior with out-of-range ionice values is undefined. Changes take effect immediately without VBD replug.
Severity
5.3 (Medium)
CWE
- CWE-20 - Improper Input Validation
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can pass arbitrary integer values to the Linux ionice binary via the class key in VBD.qos_algorithm_params. The qos_class parser at xapi_xenops.ml:595-600 accepts any integer via Other(int_of_string s), and Ionice.to_class_param passes Other x directly as the -n argument. No range validation is performed - valid range is 0-7 but negative and extreme values are accepted. Kernel behavior with out-of-range ionice values is undefined. Changes take effect immediately without VBD replug."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0060"
}
],
"title": "Arbitrary Integer Passthrough to ionice via VBD.qos_algorithm_params"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0060"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0060",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0003
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
System Domain Privilege Escalation via is_system_domain
Summary
A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can promote any VM to system domain status by writing is_system_domain=true to VM.other_config. This key has no per-key RBAC protection. A system-domain VM bypasses VBD sharing constraints (allowing concurrent write access to other VMs' virtual disks), gains access to the query_services operation, and bypasses lifecycle restrictions reserved for XAPI infrastructure components.
Severity
9.9 (Critical)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can promote any VM to system domain status by writing is_system_domain=true to VM.other_config. This key has no per-key RBAC protection. A system-domain VM bypasses VBD sharing constraints (allowing concurrent write access to other VMs\u0027 virtual disks), gains access to the query_services operation, and bypasses lifecycle restrictions reserved for XAPI infrastructure components."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.9,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.6,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:H",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-269",
"description": "Improper Privilege Management",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0003"
}
],
"title": "System Domain Privilege Escalation via is_system_domain"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0003"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0003",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0040
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
CHAP Credential Exposure via PBD.device_config
Summary
CHAP authentication credentials for iSCSI storage connections in XAPI-based hypervisors (XenServer, XCP-ng) are stored in PBD.device_config as chapuser (plaintext) and chappassword_secret (XAPI secret reference). Any pool-operator can read the PBD record to obtain the chapuser and secret reference, then call secret.get_value() to resolve the cleartext password. This enables cross-user credential theft. The credentials are also stored in plaintext in the XAPI database on disk, accessible via BOC-1 filesystem read.
Severity
6.5 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "CHAP authentication credentials for iSCSI storage connections in XAPI-based hypervisors (XenServer, XCP-ng) are stored in PBD.device_config as chapuser (plaintext) and chappassword_secret (XAPI secret reference). Any pool-operator can read the PBD record to obtain the chapuser and secret reference, then call secret.get_value() to resolve the cleartext password. This enables cross-user credential theft. The credentials are also stored in plaintext in the XAPI database on disk, accessible via BOC-1 filesystem read."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:L/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-522",
"description": "Insufficiently Protected Credentials",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0040"
}
],
"title": "CHAP Credential Exposure via PBD.device_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0040"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0040",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0077
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
VIF NIC Offload Disablement via VIF.other_config ethtool Keys
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can disable NIC offload features (TSO, GSO, etc.) on VIF backend devices by setting ethtool-tso=off and similar keys in VIF.other_config. The VIF hotplug script (vif-real:85-97) executes ethtool -K to disable offloads. This forces host CPU to perform software segmentation, increasing CPU utilization and degrading performance for co-located VMs. VIF.other_config has zero map_keys_roles entries - all ethtool keys are writable by vm-admin.
Severity
4.3 (Medium)
CWE
- CWE-862 - Missing Authorization
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can disable NIC offload features (TSO, GSO, etc.) on VIF backend devices by setting ethtool-tso=off and similar keys in VIF.other_config. The VIF hotplug script (vif-real:85-97) executes ethtool -K to disable offloads. This forces host CPU to perform software segmentation, increasing CPU utilization and degrading performance for co-located VMs. VIF.other_config has zero map_keys_roles entries - all ethtool keys are writable by vm-admin."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0077"
}
],
"title": "VIF NIC Offload Disablement via VIF.other_config ethtool Keys"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0077"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0077",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0035
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
iSCSI Initiator Identity Spoofing via Host.other_config iscsi_iqn
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can overwrite the host's iSCSI initiator identity by setting Host.other_config:iscsi_iqn to an arbitrary IQN string. The XAPI event watcher thread syncs this value to /etc/iscsi/initiatorname.iscsi without format validation. All subsequent iSCSI operations use the spoofed initiator name. Storage targets using IQN-based ACLs grant access based on the spoofed identity, enabling unauthorized access to LUNs belonging to other hosts or tenants.
Severity
6.8 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can overwrite the host\u0027s iSCSI initiator identity by setting Host.other_config:iscsi_iqn to an arbitrary IQN string. The XAPI event watcher thread syncs this value to /etc/iscsi/initiatorname.iscsi without format validation. All subsequent iSCSI operations use the spoofed initiator name. Storage targets using IQN-based ACLs grant access based on the spoofed identity, enabling unauthorized access to LUNs belonging to other hosts or tenants."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "Improper Authentication",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0035"
}
],
"title": "iSCSI Initiator Identity Spoofing via Host.other_config iscsi_iqn"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0035"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0035",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0012
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
OVS Fail-Mode Denial of Service via Network.other_config
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause a complete network denial of service on any OVS bridge by setting Network.other_config:vswitch-controller-fail-mode to secure. In secure fail mode, OVS drops all packets when no SDN controller is reachable. Since most XAPI deployments do not configure an SDN controller, this immediately drops all traffic on the bridge, affecting every VM and management connection on that network.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause a complete network denial of service on any OVS bridge by setting Network.other_config:vswitch-controller-fail-mode to secure. In secure fail mode, OVS drops all packets when no SDN controller is reachable. Since most XAPI deployments do not configure an SDN controller, this immediately drops all traffic on the bridge, affecting every VM and management connection on that network."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0012"
}
],
"title": "OVS Fail-Mode Denial of Service via Network.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0012"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0012",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0045
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Arbitrary Bond Property Injection via PIF.other_config bond-*
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary bond configuration properties by writing keys with the bond- prefix to PIF.other_config. The nm.ml module extracts any key with the bond- prefix, strips the prefix, and passes the remainder as a bond property override with zero validation on property names or values. This enables bond mode changes, timer manipulation, and injection of invalid parameters causing OVS errors and network disruption.
Severity
6.5 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary bond configuration properties by writing keys with the bond- prefix to PIF.other_config. The nm.ml module extracts any key with the bond- prefix, strips the prefix, and passes the remainder as a bond property override with zero validation on property names or values. This enables bond mode changes, timer manipulation, and injection of invalid parameters causing OVS errors and network disruption."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0045"
}
],
"title": "Arbitrary Bond Property Injection via PIF.other_config bond-*"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0045"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0045",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0072
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
SR Scan Interval Manipulation via Host.other_config auto-scan-interval
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can manipulate the SR scanning interval by writing an arbitrary float value to Host.other_config:auto-scan-interval. The value is read at xapi_sr.ml:166-168 with float_of_string and no range validation. Setting 0.001 causes continuous SR scanning (CPU/IO exhaustion); setting 999999999 effectively disables scanning (storage state blindness). The field has no map_keys_roles entries for infrastructure keys.
Severity
4.9 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can manipulate the SR scanning interval by writing an arbitrary float value to Host.other_config:auto-scan-interval. The value is read at xapi_sr.ml:166-168 with float_of_string and no range validation. Setting 0.001 causes continuous SR scanning (CPU/IO exhaustion); setting 999999999 effectively disables scanning (storage state blindness). The field has no map_keys_roles entries for infrastructure keys."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 4.9,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0072"
}
],
"title": "SR Scan Interval Manipulation via Host.other_config auto-scan-interval"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0072"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0072",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0001
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Arbitrary Host Device Mount via VBD.other_config backend-local
Summary
A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can mount any host block device as a guest virtual disk by writing an arbitrary filesystem path to VBD.other_config:backend-local. The attack requires a single API call, no exploit code, and produces no security alerts. The vulnerability collapses the entire XAPI RBAC hierarchy, granting root-equivalent access to the hypervisor host, cross-VM data exfiltration, credential theft, SSH backdoor injection, and lateral movement across shared storage.
Severity
9.9 (Critical)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can mount any host block device as a guest virtual disk by writing an arbitrary filesystem path to VBD.other_config:backend-local. The attack requires a single API call, no exploit code, and produces no security alerts. The vulnerability collapses the entire XAPI RBAC hierarchy, granting root-equivalent access to the hypervisor host, cross-VM data exfiltration, credential theft, SSH backdoor injection, and lateral movement across shared storage."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.9,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 9.4,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0001"
}
],
"title": "Arbitrary Host Device Mount via VBD.other_config backend-local"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0001"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0001",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0047
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
DNS Search Domain Injection via PIF.other_config domain
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary DNS search domains into the host resolver configuration by writing to PIF.other_config:domain. The nm.ml module reads this key, splits on commas, and passes the resulting domain list to xcp-networkd with no validation. Injected search domains cause unqualified hostname lookups to resolve through attacker-controlled domains, enabling DNS hijack of internal service discovery.
Severity
6.1 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary DNS search domains into the host resolver configuration by writing to PIF.other_config:domain. The nm.ml module reads this key, splits on commas, and passes the resulting domain list to xcp-networkd with no validation. Injected search domains cause unqualified hostname lookups to resolve through attacker-controlled domains, enabling DNS hijack of internal service discovery."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0047"
}
],
"title": "DNS Search Domain Injection via PIF.other_config domain"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0047"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0047",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0020
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
CBT Metadata Corruption via VDI.other_config content_id
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can corrupt Change Block Tracking (CBT) metadata by injecting a crafted content_id value into VDI.other_config. The content_id key is used by the XAPI storage bridge to track VDI content identity across activate/deactivate/clone cycles. Incremental backup solutions use content_id to determine the base snapshot for changed-block calculations. A forged UUID causes the backup system to use an incorrect base, missing changed blocks and producing backups that silently lose data on restore.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can corrupt Change Block Tracking (CBT) metadata by injecting a crafted content_id value into VDI.other_config. The content_id key is used by the XAPI storage bridge to track VDI content identity across activate/deactivate/clone cycles. Incremental backup solutions use content_id to determine the base snapshot for changed-block calculations. A forged UUID causes the backup system to use an incorrect base, missing changed blocks and producing backups that silently lose data on restore."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0020"
}
],
"title": "CBT Metadata Corruption via VDI.other_config content_id"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0020"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0020",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0064
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Database Field Poisoning via VDI.xenstore_data Arbitrary Keys
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary key-value pairs into VDI.xenstore_data, a field designed for SM backend use. The field has zero map_keys_roles, zero write-time validation, and zero sanitization. Injected data persists in the XAPI database and is visible to all API consumers. Downstream systems (backup tools, inventory scanners, orchestration platforms) may trust the values as SM-generated metadata. The xe CLI reports this field as read-only, but programmatic API access bypasses this restriction.
Severity
5.3 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary key-value pairs into VDI.xenstore_data, a field designed for SM backend use. The field has zero map_keys_roles, zero write-time validation, and zero sanitization. Injected data persists in the XAPI database and is visible to all API consumers. Downstream systems (backup tools, inventory scanners, orchestration platforms) may trust the values as SM-generated metadata. The xe CLI reports this field as read-only, but programmatic API access bypasses this restriction."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0064"
}
],
"title": "Database Field Poisoning via VDI.xenstore_data Arbitrary Keys"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0064"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0064",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0067
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Cross-Pool Metadata Injection via VDI.xenstore_data on Pool Join
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can poison VDI.xenstore_data on a source pool, and the poisoned metadata crosses into a target pool during pool join or cross-pool migration. The pool join code at xapi_pool.ml:1215 copies VDI records including xenstore_data without re-validation or sanitization. This enables a compromised vm-admin on one pool to inject attacker-controlled storage metadata into a separate, previously uncompromised pool.
Severity
5.3 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can poison VDI.xenstore_data on a source pool, and the poisoned metadata crosses into a target pool during pool join or cross-pool migration. The pool join code at xapi_pool.ml:1215 copies VDI records including xenstore_data without re-validation or sanitization. This enables a compromised vm-admin on one pool to inject attacker-controlled storage metadata into a separate, previously uncompromised pool."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0067"
}
],
"title": "Cross-Pool Metadata Injection via VDI.xenstore_data on Pool Join"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0067"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0067",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0024
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
NFS Mount Option Injection via PBD.device_config
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary NFS mount options via PBD.device_config:options when creating an NFS storage repository. The NFSSR driver appends these options directly to the mount.nfs command without sanitization. An attacker can inject sec=none to disable NFS authentication, noac to cause performance denial of service, or ro to force read-only access. The attack was confirmed via live testing with all checks passing.
Severity
CWE
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary NFS mount options via PBD.device_config:options when creating an NFS storage repository. The NFSSR driver appends these options directly to the mount.nfs command without sanitization. An attacker can inject sec=none to disable NFS authentication, noac to cause performance denial of service, or ro to force read-only access. The attack was confirmed via live testing with all checks passing."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 7.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:L/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-88",
"description": "Improper Neutralization of Argument Delimiters in a Command",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0024"
}
],
"title": "NFS Mount Option Injection via PBD.device_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0024"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0024",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0069
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Hypervisor Security Feature Manipulation via VM.platform (nx/hap)
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can disable CPU security features by writing to VM.platform keys. Setting nx=false removes DEP protection, hap=false forces shadow paging, nested-virt=true expands the hypervisor attack surface, and extreme max_grant_frames/max_maptrack_frames values cause resource exhaustion. The field has zero map_keys_roles entries - all security-critical hypervisor keys are writable by the lowest delegated management role.
Severity
5.3 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can disable CPU security features by writing to VM.platform keys. Setting nx=false removes DEP protection, hap=false forces shadow paging, nested-virt=true expands the hypervisor attack surface, and extreme max_grant_frames/max_maptrack_frames values cause resource exhaustion. The field has zero map_keys_roles entries - all security-critical hypervisor keys are writable by the lowest delegated management role."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0069"
}
],
"title": "Hypervisor Security Feature Manipulation via VM.platform (nx/hap)"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0069"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0069",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0088
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Int64 Overflow in bytes_per_interval via VIF.qos_algorithm_params
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params kbps and timeslice_us values that cause Int64 overflow in the bytes_per_interval computation at device.ml:835-845. OCaml silently wraps on integer overflow, producing unexpected rate values. xenopsd bounds checking catches most overflow results, but edge cases where the wrapped value falls within the valid range produce rate limits unrelated to the configured kbps. The field has zero map_keys_roles entries.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params kbps and timeslice_us values that cause Int64 overflow in the bytes_per_interval computation at device.ml:835-845. OCaml silently wraps on integer overflow, producing unexpected rate values. xenopsd bounds checking catches most overflow results, but edge cases where the wrapped value falls within the valid range produce rate limits unrelated to the configured kbps. The field has zero map_keys_roles entries."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 2.3,
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-190",
"description": "Integer Overflow or Wraparound",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0088"
}
],
"title": "Int64 Overflow in bytes_per_interval via VIF.qos_algorithm_params"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0088"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0088",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0039
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Filesystem Layout Manipulation via SR.sm_config nosubdir/subdir
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can manipulate the filesystem layout of NFS and MooseFS storage repositories by modifying the nosubdir or subdir key in SR.sm_config after SR creation. Changing nosubdir causes the driver to look for VDIs in the wrong directory. All VDIs appear missing, causing VM boot failures and complete data inaccessibility for all VMs on the affected SR. The attack is reversible but causes service disruption.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can manipulate the filesystem layout of NFS and MooseFS storage repositories by modifying the nosubdir or subdir key in SR.sm_config after SR creation. Changing nosubdir causes the driver to look for VDIs in the wrong directory. All VDIs appear missing, causing VM boot failures and complete data inaccessibility for all VMs on the affected SR. The attack is reversible but causes service disruption."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 7.0,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:L/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0039"
}
],
"title": "Filesystem Layout Manipulation via SR.sm_config nosubdir/subdir"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0039"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0039",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0017
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Static Route Injection via Network.other_config
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary static routes into the host routing table by setting Network.other_config:static-routes to attacker-controlled subnet/gateway pairs. The value is parsed by nm.ml and applied directly to the bridge interface with no validation on subnet, gateway reachability, or conflicts with existing routes. Injected routes redirect storage network traffic, management traffic, or cloud subnet traffic through an attacker-controlled gateway.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary static routes into the host routing table by setting Network.other_config:static-routes to attacker-controlled subnet/gateway pairs. The value is parsed by nm.ml and applied directly to the bridge interface with no validation on subnet, gateway reachability, or conflicts with existing routes. Injected routes redirect storage network traffic, management traffic, or cloud subnet traffic through an attacker-controlled gateway."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.6,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 7.0,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:L/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0017"
}
],
"title": "Static Route Injection via Network.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0017"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0017",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0051
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Config Drive Misidentification via VDI.other_config config-drive
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can mark any VDI as a cloud-init config drive by setting config-drive=true in VDI.other_config. The key is defined in xapi_globs.ml as a sync key and consumed during migration and import operations. Guest cloud-init agents misinterpret the flagged VDI's contents as trusted hypervisor-provided metadata, potentially initializing the guest with attacker-controlled configuration.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can mark any VDI as a cloud-init config drive by setting config-drive=true in VDI.other_config. The key is defined in xapi_globs.ml as a sync key and consumed during migration and import operations. Guest cloud-init agents misinterpret the flagged VDI\u0027s contents as trusted hypervisor-provided metadata, potentially initializing the guest with attacker-controlled configuration."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 2.3,
"baseSeverity": "LOW",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0051"
}
],
"title": "Config Drive Misidentification via VDI.other_config config-drive"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0051"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0051",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0033
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Rate Limit Bypass via VIF.qos_algorithm_params Large kbps Overflow
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params:kbps to an extremely large value that causes bytes_per_interval to exceed 0xffffffffL during computation in xenopsd. xenopsd correctly rejects the out-of-range value but does so silently with only a debug-level log. XAPI continues to show the configured rate limit in the database. The VM operates without network rate limiting while the management plane reports it as enforced.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can set VIF.qos_algorithm_params:kbps to an extremely large value that causes bytes_per_interval to exceed 0xffffffffL during computation in xenopsd. xenopsd correctly rejects the out-of-range value but does so silently with only a debug-level log. XAPI continues to show the configured rate limit in the database. The VM operates without network rate limiting while the management plane reports it as enforced."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-190",
"description": "Integer Overflow or Wraparound",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0033"
}
],
"title": "Rate Limit Bypass via VIF.qos_algorithm_params Large kbps Overflow"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0033"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0033",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0046
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
MTU Manipulation / Network Partition via PIF.other_config
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause network partition by setting the mtu key in PIF.other_config to an extreme value. The nm.ml module parses the value with int_of_string and applies it as the interface MTU with no range validation. Setting MTU too low on the management interface causes packet drops that partition the host from the pool. On HA-enabled pools, management network partitioning triggers HA fencing.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause network partition by setting the mtu key in PIF.other_config to an extreme value. The nm.ml module parses the value with int_of_string and applies it as the interface MTU with no range validation. Setting MTU too low on the management interface causes packet drops that partition the host from the pool. On HA-enabled pools, management network partitioning triggers HA fencing."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0046"
}
],
"title": "MTU Manipulation / Network Partition via PIF.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0046"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0046",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0059
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Multi-Tenant Trust Confusion via VM.xenstore_data
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject vm-data/* keys into VM.xenstore_data that modify guest behavior across trust boundaries in delegated VM administration environments. Guest OSes treat all vm-data/ entries as trusted hypervisor configuration with no mechanism to distinguish legitimate data from vm-admin-injected data. This enables supply chain attacks via installation source redirection, configuration endpoint hijacking, and credential injection in multi-tenant pools.
Severity
5.3 (Medium)
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject vm-data/* keys into VM.xenstore_data that modify guest behavior across trust boundaries in delegated VM administration environments. Guest OSes treat all vm-data/ entries as trusted hypervisor configuration with no mechanism to distinguish legitimate data from vm-admin-injected data. This enables supply chain attacks via installation source redirection, configuration endpoint hijacking, and credential injection in multi-tenant pools."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0059"
}
],
"title": "Multi-Tenant Trust Confusion via VM.xenstore_data"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0059"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0059",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0013
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Pool-Wide OVS Fail-Mode Denial of Service via Pool.other_config
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause a complete network outage across every host in the pool by setting Pool.other_config:vswitch-controller-fail-mode to secure. This pool-level key serves as the default fail mode for every OVS bridge without a per-network override. Without an SDN controller - the common deployment case - all network traffic is dropped on all bridges across all hosts pool-wide, affecting every VM, management connection, and storage path in the pool.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can cause a complete network outage across every host in the pool by setting Pool.other_config:vswitch-controller-fail-mode to secure. This pool-level key serves as the default fail mode for every OVS bridge without a per-network override. Without an SDN controller - the common deployment case - all network traffic is dropped on all bridges across all hosts pool-wide, affecting every VM, management connection, and storage path in the pool."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0013"
}
],
"title": "Pool-Wide OVS Fail-Mode Denial of Service via Pool.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0013"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0013",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0029
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
SR-IOV VIF Whitelist Bypass via VIF.other_config
Summary
On SR-IOV-backed VIFs in XAPI-based hypervisors (XenServer, XCP-ng), all VIF.other_config keys bypass the whitelist filter and are written unfiltered to guest-readable xenstore. The standard VIF path (Device.Vif.add) applies a 7-key whitelist; the SR-IOV path (Device.NetSriovVf.add) does not apply this filter. This breaks security equivalence between standard and SR-IOV VIFs, allowing a vm-admin to inject arbitrary key-value pairs into guest-readable xenstore on SR-IOV networks.
Severity
CWE
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "On SR-IOV-backed VIFs in XAPI-based hypervisors (XenServer, XCP-ng), all VIF.other_config keys bypass the whitelist filter and are written unfiltered to guest-readable xenstore. The standard VIF path (Device.Vif.add) applies a 7-key whitelist; the SR-IOV path (Device.NetSriovVf.add) does not apply this filter. This breaks security equivalence between standard and SR-IOV VIFs, allowing a vm-admin to inject arbitrary key-value pairs into guest-readable xenstore on SR-IOV networks."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-200",
"description": "Exposure of Sensitive Information to an Unauthorized Actor",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0029"
}
],
"title": "SR-IOV VIF Whitelist Bypass via VIF.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0029"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0029",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0026
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Python Module Import Injection via Host.other_config multipathhandle
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject a controlled Python module name via Host.other_config:multipathhandle. The SM driver SR._mpathinit() passes this value to Python __import__() as mpath_<value>. Combined with a file write primitive (provided by BOC-1), an attacker places a malicious .py file in /opt/xensource/sm/ and triggers import as root during the next SR operation. Standalone exploitation requires pool-operator plus an independent file write capability.
Severity
CWE
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can inject a controlled Python module name via Host.other_config:multipathhandle. The SM driver SR._mpathinit() passes this value to Python __import__() as mpath_\u003cvalue\u003e. Combined with a file write primitive (provided by BOC-1), an attacker places a malicious .py file in /opt/xensource/sm/ and triggers import as root during the next SR operation. Standalone exploitation requires pool-operator plus an independent file write capability."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.2,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-913",
"description": "Improper Control of Dynamically-Managed Code Resources",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0026"
}
],
"title": "Python Module Import Injection via Host.other_config multipathhandle"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0026"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0026",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0080
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
I/O Scheduler Sysfs Injection via SR.other_config scheduler
Summary
A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can write an arbitrary string to the kernel I/O scheduler sysfs interface by setting the scheduler key in SR.other_config. The SM driver reads the value at SR.py:203-224 and passes it to util.set_scheduler, which writes it to /sys/block/*/queue/scheduler with zero XAPI-side validation. The kernel validates the value (rejecting unknown schedulers), limiting direct impact. The concern is the architectural pattern: user-controlled XAPI data flows directly to a kernel control interface. The field has no map_keys_roles entries for infrastructure keys.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A pool-operator in XAPI-based hypervisors (XenServer, XCP-ng) can write an arbitrary string to the kernel I/O scheduler sysfs interface by setting the scheduler key in SR.other_config. The SM driver reads the value at SR.py:203-224 and passes it to util.set_scheduler, which writes it to /sys/block/*/queue/scheduler with zero XAPI-side validation. The kernel validates the value (rejecting unknown schedulers), limiting direct impact. The concern is the architectural pattern: user-controlled XAPI data flows directly to a kernel control interface. The field has no map_keys_roles entries for infrastructure keys."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 3.8,
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0080"
}
],
"title": "I/O Scheduler Sysfs Injection via SR.other_config scheduler"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0080"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0080",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0022
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Real-Time I/O Class Abuse via VBD.qos_algorithm_params - Cross-VM Starvation
Summary
A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can set the real-time I/O scheduling class on VBD kernel threads by writing sched=rt and class=highest to VBD.qos_algorithm_params. xenopsd invokes ionice -c1 -n0 on the affected threads, granting strict priority over all best-effort and idle I/O on the host. This starves I/O for every other VM on the same host. The change takes effect immediately without VBD replug and produces no security alert.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can set the real-time I/O scheduling class on VBD kernel threads by writing sched=rt and class=highest to VBD.qos_algorithm_params. xenopsd invokes ionice -c1 -n0 on the affected threads, granting strict priority over all best-effort and idle I/O on the host. This starves I/O for every other VM on the same host. The change takes effect immediately without VBD replug and produces no security alert."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 8.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0022"
}
],
"title": "Real-Time I/O Class Abuse via VBD.qos_algorithm_params - Cross-VM Starvation"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0022"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0022",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0058
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Xenstore Quota Exhaustion via VM.xenstore_data
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can exhaust a guest domain's xenstore quota by injecting a large number of vm-data/* keys into VM.xenstore_data. Xenstore enforces a per-domain quota shared with guest agent data. When injected data consumes the quota, the guest's own xenstore operations fail, disrupting PV drivers, network configuration, and guest agent communication. The field has zero map_keys_roles entries and no value length limits.
Severity
5.3 (Medium)
CWE
- CWE-400 - Uncontrolled Resource Consumption
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can exhaust a guest domain\u0027s xenstore quota by injecting a large number of vm-data/* keys into VM.xenstore_data. Xenstore enforces a per-domain quota shared with guest agent data. When injected data consumes the quota, the guest\u0027s own xenstore operations fail, disrupting PV drivers, network configuration, and guest agent communication. The field has zero map_keys_roles entries and no value length limits."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0058"
}
],
"title": "Xenstore Quota Exhaustion via VM.xenstore_data"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0058"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0058",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
MOKSHA-2026-0007
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
EPSS
VEX
Title
Backend-Kind I/O Driver Type Confusion via VBD.other_config
Summary
A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can change the storage I/O backend driver for any VBD by writing to VBD.other_config:backend-kind. This key selects whether kernel blkback or userspace tapdisk handles I/O. An attacker can force a VBD to use an unexpected backend, bypassing tapdisk-level access controls, monitoring, and VHD chain processing. The key has no per-key RBAC protection and accepts arbitrary values.
Severity
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
{
"containers": {
"cna": {
"affected": [
{
"product": "XenServer",
"vendor": "Cloud Software Group",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
},
{
"product": "XCP-ng",
"vendor": "Vates",
"versions": [
{
"status": "affected",
"version": "all",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jakob Wolffhechel, Moksha"
}
],
"descriptions": [
{
"lang": "en",
"value": "A user with the vm-admin role in XAPI-based hypervisors (XenServer, XCP-ng) can change the storage I/O backend driver for any VBD by writing to VBD.other_config:backend-kind. This key selects whether kernel blkback or userspace tapdisk handles I/O. An attacker can force a VBD to use an unexpected backend, bypassing tapdisk-level access controls, monitoring, and VHD chain processing. The key has no per-key RBAC protection and accepts arbitrary values."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:L/SA:N",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0007"
}
],
"title": "Backend-Kind I/O Driver Type Confusion via VBD.other_config"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0007"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0007",
"datePublished": "2026-04-24T06:00:00Z",
"state": "PUBLISHED",
"x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}