Viridian STIMER division by zero

The logic to handle periodic Viridian STIMERs performs a division with an

unchecked user-controlled divisor value, that can be set to zero to cause a #DE

fault.

Affected products

Xen

Xen

consult Xen advisory XSA-504 - UNKNOWN

References

xenbits.xenproject.org

https://xenbits.xenproject.org/xsa/advisory-504.html

GitHub Security Advisories

GHSA-248q-w8jq-jxj9

The logic to handle periodic Viridian STIMERs performs a division with an unchecked user...

https://github.com/advisories/GHSA-248q-w8jq-jxj9

The logic to handle periodic Viridian STIMERs performs a division with an unchecked user-controlled divisor value, that can be set to zero to cause a #DE fault.

nvd.nist.gov

https://nvd.nist.gov/vuln/detail/CVE-2026-62431

xenbits.xenproject.org

https://xenbits.xenproject.org/xsa/advisory-504.html

xenbits.xen.org

http://xenbits.xen.org/xsa/advisory-504.html

openwall.com

http://www.openwall.com/lists/oss-security/2026/07/28/20

github.com

https://github.com/advisories/GHSA-248q-w8jq-jxj9

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-62431

Click to expand

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-62431",
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "dateUpdated": "2026-07-28T13:34:13.081Z",
    "dateReserved": "2026-07-14T10:28:12.655Z",
    "datePublished": "2026-07-28T12:32:43.849Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN",
        "dateUpdated": "2026-07-28T12:32:43.849Z"
      },
      "datePublic": "2026-07-28T12:00:00.000Z",
      "title": "Viridian STIMER division by zero",
      "descriptions": [
        {
          "lang": "en",
          "value": "The logic to handle periodic Viridian STIMERs performs a division with an\nunchecked user-controlled divisor value, that can be set to zero to cause a #DE\nfault."
        }
      ],
      "affected": [
        {
          "vendor": "Xen",
          "product": "Xen",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "consult Xen advisory XSA-504",
              "status": "unknown"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-504.html"
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "Enabling Viridian STIMERs to unprivileged HVM guests can result in a Denial\nof Service (DoS) affecting the entire host."
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "All Xen versions from 4.13 onwards are vulnerable.  Xen versions 4.12 and\nearlier are not vulnerable.\n\nOnly HVM guests with Viridian STIMERs enabled can trigger the vulnerability."
        }
      ],
      "workarounds": [
        {
          "lang": "en",
          "value": "Not enabling Viridian STIMERs for HVM guests will avoid the vulnerability.\n\nNote Viridian extensions are not enabled by default."
        }
      ]
    },
    "adp": [
      {
        "providerMetadata": {
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE",
          "dateUpdated": "2026-07-28T13:34:13.081Z"
        },
        "title": "CVE Program Container",
        "references": [
          {
            "url": "http://xenbits.xen.org/xsa/advisory-504.html"
          }
        ]
      }
    ]
  }
}