CVE-2026-31593 (GCVE-0-2026-31593)
Vulnerability from cvelistv5 – Published: 2026-04-24 14:42 – Updated: 2026-04-27 11:01
VLAI?
Title
KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU
Summary
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU
Reject synchronizing vCPU state to its associated VMSA if the vCPU has
already been launched, i.e. if the VMSA has already been encrypted. On a
host with SNP enabled, accessing guest-private memory generates an RMP #PF
and panics the host.
BUG: unable to handle page fault for address: ff1276cbfdf36000
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163
SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]
Oops: Oops: 0003 [#1] SMP NOPTI
CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023
RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]
Call Trace:
<TASK>
snp_launch_update_vmsa+0x19d/0x290 [kvm_amd]
snp_launch_finish+0xb6/0x380 [kvm_amd]
sev_mem_enc_ioctl+0x14e/0x720 [kvm_amd]
kvm_arch_vm_ioctl+0x837/0xcf0 [kvm]
kvm_vm_ioctl+0x3fd/0xcc0 [kvm]
__x64_sys_ioctl+0xa3/0x100
x64_sys_call+0xfe0/0x2350
do_syscall_64+0x81/0x10f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ffff673287d
</TASK>
Note, the KVM flaw has been present since commit ad73109ae7ec ("KVM: SVM:
Provide support to launch and run an SEV-ES guest"), but has only been
actively dangerous for the host since SNP support was added. With SEV-ES,
KVM would "just" clobber guest state, which is totally fine from a host
kernel perspective since userspace can clobber guest state any time before
sev_launch_update_vmsa().
Severity ?
No CVSS data available.
Assigner
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Affected:
ad27ce155566f2b4400fa865859834592bd18777 , < c9609847ae65ca36233077c2b6cb2bc0fb37c77a
(git)
Affected: ad27ce155566f2b4400fa865859834592bd18777 , < 692fdf05e55fa03960a1278afdc2478c12daea13 (git) Affected: ad27ce155566f2b4400fa865859834592bd18777 , < 6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab (git) Affected: ad27ce155566f2b4400fa865859834592bd18777 , < 8f85a4885eee8cb495961ffa371a91828afb9445 (git) Affected: ad27ce155566f2b4400fa865859834592bd18777 , < 9b9f7962e3e879d12da2bf47e02a24ec51690e3d (git) |
||
{
"containers": {
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"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
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"versionType": "git"
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{
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"versionType": "git"
},
{
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],
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},
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"version": "0",
"versionType": "semver"
},
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"version": "6.12.83",
"versionType": "semver"
},
{
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"version": "6.18.24",
"versionType": "semver"
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{
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"status": "unaffected",
"version": "6.19.14",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "7.0.1",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1-rc1",
"versionType": "original_commit_for_fix"
}
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}
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"cpeApplicability": [
{
"nodes": [
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU\n\nReject synchronizing vCPU state to its associated VMSA if the vCPU has\nalready been launched, i.e. if the VMSA has already been encrypted. On a\nhost with SNP enabled, accessing guest-private memory generates an RMP #PF\nand panics the host.\n\n BUG: unable to handle page fault for address: ff1276cbfdf36000\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x80000003) - RMP violation\n PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163\n SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]\n Oops: Oops: 0003 [#1] SMP NOPTI\n CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE\n Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023\n RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]\n Call Trace:\n \u003cTASK\u003e\n snp_launch_update_vmsa+0x19d/0x290 [kvm_amd]\n snp_launch_finish+0xb6/0x380 [kvm_amd]\n sev_mem_enc_ioctl+0x14e/0x720 [kvm_amd]\n kvm_arch_vm_ioctl+0x837/0xcf0 [kvm]\n kvm_vm_ioctl+0x3fd/0xcc0 [kvm]\n __x64_sys_ioctl+0xa3/0x100\n x64_sys_call+0xfe0/0x2350\n do_syscall_64+0x81/0x10f0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7ffff673287d\n \u003c/TASK\u003e\n\nNote, the KVM flaw has been present since commit ad73109ae7ec (\"KVM: SVM:\nProvide support to launch and run an SEV-ES guest\"), but has only been\nactively dangerous for the host since SNP support was added. With SEV-ES,\nKVM would \"just\" clobber guest state, which is totally fine from a host\nkernel perspective since userspace can clobber guest state any time before\nsev_launch_update_vmsa()."
}
],
"providerMetadata": {
"dateUpdated": "2026-04-27T11:01:09.844Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a"
},
{
"url": "https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13"
},
{
"url": "https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab"
},
{
"url": "https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445"
},
{
"url": "https://git.kernel.org/stable/c/9b9f7962e3e879d12da2bf47e02a24ec51690e3d"
}
],
"title": "KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-31593",
"datePublished": "2026-04-24T14:42:19.567Z",
"dateReserved": "2026-03-09T15:48:24.121Z",
"dateUpdated": "2026-04-27T11:01:09.844Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-31593",
"date": "2026-05-04",
"epss": "0.00013",
"percentile": "0.02201"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-31593\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-04-24T15:16:36.957\",\"lastModified\":\"2026-04-29T14:29:38.163\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nKVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU\\n\\nReject synchronizing vCPU state to its associated VMSA if the vCPU has\\nalready been launched, i.e. if the VMSA has already been encrypted. On a\\nhost with SNP enabled, accessing guest-private memory generates an RMP #PF\\nand panics the host.\\n\\n BUG: unable to handle page fault for address: ff1276cbfdf36000\\n #PF: supervisor write access in kernel mode\\n #PF: error_code(0x80000003) - RMP violation\\n PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163\\n SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]\\n Oops: Oops: 0003 [#1] SMP NOPTI\\n CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE\\n Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\\n Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023\\n RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]\\n Call Trace:\\n \u003cTASK\u003e\\n snp_launch_update_vmsa+0x19d/0x290 [kvm_amd]\\n snp_launch_finish+0xb6/0x380 [kvm_amd]\\n sev_mem_enc_ioctl+0x14e/0x720 [kvm_amd]\\n kvm_arch_vm_ioctl+0x837/0xcf0 [kvm]\\n kvm_vm_ioctl+0x3fd/0xcc0 [kvm]\\n __x64_sys_ioctl+0xa3/0x100\\n x64_sys_call+0xfe0/0x2350\\n do_syscall_64+0x81/0x10f0\\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n RIP: 0033:0x7ffff673287d\\n \u003c/TASK\u003e\\n\\nNote, the KVM flaw has been present since commit ad73109ae7ec (\\\"KVM: SVM:\\nProvide support to launch and run an SEV-ES guest\\\"), but has only been\\nactively dangerous for the host since SNP support was added. With SEV-ES,\\nKVM would \\\"just\\\" clobber guest state, which is totally fine from a host\\nkernel perspective since userspace can clobber guest state any time before\\nsev_launch_update_vmsa().\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.11\",\"versionEndExcluding\":\"6.12.83\",\"matchCriteriaId\":\"ABF3F6D0-27D6-43E7-BF38-1B493B03EC1F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.24\",\"matchCriteriaId\":\"8126B8B8-6D0B-4443-86C1-672AEE893555\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.19\",\"versionEndExcluding\":\"6.19.14\",\"matchCriteriaId\":\"D6A8A074-BBF4-4803-ABED-519A839435BB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"7.0\",\"versionEndExcluding\":\"7.0.1\",\"matchCriteriaId\":\"9B5888AB-7403-4335-89E4-21CC0B48366A\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/9b9f7962e3e879d12da2bf47e02a24ec51690e3d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}"
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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