Vulnerability-Lookup

GHSA-2HV5-3QJG-GJQR

Vulnerability from github – Published: 2026-07-28 15:32 – Updated: 2026-07-28 18:33

Details

Xenstore, to have an up-to-date picture of the entire system, wants to know of domains appearing and disappearing. To make this more robust, a new XEN_DOMCTL_get_domain_state was introduced. The management of the bitmap underlying that operation is tied into the binding of the VIRQ_DOM_EXC virtual IRQ. Unfortunately an error path there would tear down the bitmap even in cases when it wasn't set up. Unprivileged domains can trigger that error path.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-42492"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-459"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-28T13:18:32Z",
    "severity": "HIGH"
  },
  "details": "Xenstore, to have an up-to-date picture of the entire system, wants to\nknow of domains appearing and disappearing.  To make this more robust, a\nnew XEN_DOMCTL_get_domain_state was introduced.  The management of the\nbitmap underlying that operation is tied into the binding of the\nVIRQ_DOM_EXC virtual IRQ.  Unfortunately an error path there would tear\ndown the bitmap even in cases when it wasn\u0027t set up.  Unprivileged domains\ncan trigger that error path.",
  "id": "GHSA-2hv5-3qjg-gjqr",
  "modified": "2026-07-28T18:33:02Z",
  "published": "2026-07-28T15:32:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42492"
    },
    {
      "type": "WEB",
      "url": "https://xenbits.xenproject.org/xsa/advisory-496.html"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/28/13"
    },
    {
      "type": "WEB",
      "url": "http://xenbits.xen.org/xsa/advisory-496.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-42492 (GCVE-0-2026-42492)

Vulnerability from cvelistv5 – Published: 2026-07-28 12:31 – Updated: 2026-07-28 16:33

Title

vIRQ event channel binding may break Xenstore

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-459 - Incomplete Cleanup

Assigner

XEN

References

3 references

URL	Tags
https://xenbits.xenproject.org/xsa/advisory-496.html
http://xenbits.xen.org/xsa/advisory-496.html
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

Vendor	Product	Version
Xen	Xen	Unknown: consult Xen advisory XSA-496

Date Public

2026-07-28 12:00

Credits

This issue was discovered by Grygorii Strashko of EPAM.

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JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-07-28T16:33:22.683Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://xenbits.xen.org/xsa/advisory-496.html"
          },
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/07/28/13"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42492",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-28T15:56:49.876014Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-459",
                "description": "CWE-459 Incomplete Cleanup",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-28T15:56:54.437Z",
          "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-496"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "Xen 4.21 and onwards are vulnerable.  Xen 4.20 and older are not\nvulnerable."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "This issue was discovered by Grygorii Strashko of EPAM."
        }
      ],
      "datePublic": "2026-07-28T12:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Xenstore, to have an up-to-date picture of the entire system, wants to\nknow of domains appearing and disappearing.  To make this more robust, a\nnew XEN_DOMCTL_get_domain_state was introduced.  The management of the\nbitmap underlying that operation is tied into the binding of the\nVIRQ_DOM_EXC virtual IRQ.  Unfortunately an error path there would tear\ndown the bitmap even in cases when it wasn\u0027t set up.  Unprivileged domains\ncan trigger that error path."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "An unprivileged domain can affect the operation of Xenstore, potentially\nleading to a Denial of Service (DoS) affecting the entire host.  A\nhypervisor crash with similar host wide effect also is possible, albeit\nunlikely."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-28T12:31:28.304Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-496.html"
        }
      ],
      "title": "vIRQ event channel binding may break Xenstore",
      "workarounds": [
        {
          "lang": "en",
          "value": "There is no known mitigation."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2026-42492",
    "datePublished": "2026-07-28T12:31:28.304Z",
    "dateReserved": "2026-04-27T14:20:24.139Z",
    "dateUpdated": "2026-07-28T16:33:22.683Z",
    "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.

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GHSA-2HV5-3QJG-GJQR

CVE-2026-42492 (GCVE-0-2026-42492)

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Sightings

Nomenclature