Vulnerability-Lookup

GHSA-9XQ7-8P44-P7P4

Vulnerability from github – Published: 2026-06-18 15:32 – Updated: 2026-06-18 18:35

Details

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]

To create and manage guests, domctl operations are used by the control domain, a possible Xenstore domain, or by a domain controlling a particular guest. Some of these operations may not be executed in parallel, so a system-wide lock is used. The way that lock is acquired is, however, not providing any fairness. This is CVE-2026-42489.

Furthermore, with XSM/Flask in use, the lock acquire will, for some operations, occur ahead of any permission checking. This is CVE-2026-42490.

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-42490"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-667"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-18T14:17:25Z",
    "severity": "MODERATE"
  },
  "details": "[This CNA information record relates to multiple CVEs; the\ntext explains which aspects/vulnerabilities correspond to which CVE.]\n\nTo create and manage guests, domctl operations are used by the control\ndomain, a possible Xenstore domain, or by a domain controlling a\nparticular guest.  Some of these operations may not be executed in\nparallel, so a system-wide lock is used.  The way that lock is acquired\nis, however, not providing any fairness.  This is CVE-2026-42489.\n\nFurthermore, with XSM/Flask in use, the lock acquire will, for some\noperations, occur ahead of any permission checking.  This is\nCVE-2026-42490.",
  "id": "GHSA-9xq7-8p44-p7p4",
  "modified": "2026-06-18T18:35:21Z",
  "published": "2026-06-18T15:32:02Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42490"
    },
    {
      "type": "WEB",
      "url": "https://xenbits.xenproject.org/xsa/advisory-492.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-42490 (GCVE-0-2026-42490)

Vulnerability from cvelistv5 – Published: 2026-06-18 13:47 – Updated: 2026-06-18 15:04

Title

domctl lock open to abuse

Summary

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To create and manage guests, domctl operations are used by the control domain, a possible Xenstore domain, or by a domain controlling a particular guest. Some of these operations may not be executed in parallel, so a system-wide lock is used. The way that lock is acquired is, however, not providing any fairness. This is CVE-2026-42489. Furthermore, with XSM/Flask in use, the lock acquire will, for some operations, occur ahead of any permission checking. This is CVE-2026-42490.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-18 15:04 UTC

CWE

CWE-667 - Improper Locking

Assigner

XEN mitre root

References

1 reference

URL	Tags
https://xenbits.xenproject.org/xsa/advisory-492.html

Impacted products

1 product

Vendor	Product	Version
Xen	Xen	Unknown: consult Xen advisory XSA-492

Date Public

2026-06-09 12:00

Credits

This issue was discovered by Andrew Cooper of Citrix.

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42490",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-18T15:04:47.308725Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-667",
                "description": "CWE-667 Improper Locking",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-18T15:04:50.692Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "product": "Xen",
          "vendor": "Xen",
          "versions": [
            {
              "status": "unknown",
              "version": "consult Xen advisory XSA-492"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "All Xen versions from 3.3 onwards are vulnerable.  Earlier versions use\na different locking operation, but may also be vulnerable."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "This issue was discovered by Andrew Cooper of Citrix."
        }
      ],
      "datePublic": "2026-06-09T12:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "[This CNA information record relates to multiple CVEs; the\ntext explains which aspects/vulnerabilities correspond to which CVE.]\n\nTo create and manage guests, domctl operations are used by the control\ndomain, a possible Xenstore domain, or by a domain controlling a\nparticular guest.  Some of these operations may not be executed in\nparallel, so a system-wide lock is used.  The way that lock is acquired\nis, however, not providing any fairness.  This is CVE-2026-42489.\n\nFurthermore, with XSM/Flask in use, the lock acquire will, for some\noperations, occur ahead of any permission checking.  This is\nCVE-2026-42490."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "A less privileged entity may stall an equally or more privileged entity,\npotentially leading to a Denial od Service (DoS) of up to the entire\nhost."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-18T13:47:13.257Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-492.html"
        }
      ],
      "title": "domctl lock open to abuse",
      "workarounds": [
        {
          "lang": "en",
          "value": "There is no known mitigation."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2026-42490",
    "datePublished": "2026-06-18T13:47:13.257Z",
    "dateReserved": "2026-04-27T14:20:24.139Z",
    "dateUpdated": "2026-06-18T15:04:50.692Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.