CVE-2026-62431 (GCVE-0-2026-62431)

Vulnerability from cvelistv5 – Published: 2026-07-28 12:32 – Updated: 2026-07-28 16:33
VLAI
Title
Viridian STIMER division by zero
Summary
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.
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
Assigner
XEN
References
Impacted products
Vendor Product Version
Xen Xen Unknown: consult Xen advisory XSA-504
Create a notification for this product.
Date Public
2026-07-28 12:00
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-07-28T16:33:31.447Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://xenbits.xen.org/xsa/advisory-504.html"
          },
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/07/28/20"
          }
        ],
        "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-2026-62431",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-28T15:49:03.810668Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-369",
                "description": "CWE-369 Divide By Zero",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-28T15:49:09.743Z",
          "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-504"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "datePublic": "2026-07-28T12:00:00.000Z",
      "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."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "Enabling Viridian STIMERs to unprivileged HVM guests can result in a Denial\nof Service (DoS) affecting the entire host."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-28T12:32:43.849Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-504.html"
        }
      ],
      "title": "Viridian STIMER division by zero",
      "workarounds": [
        {
          "lang": "en",
          "value": "Not enabling Viridian STIMERs for HVM guests will avoid the vulnerability.\n\nNote Viridian extensions are not enabled by default."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2026-62431",
    "datePublished": "2026-07-28T12:32:43.849Z",
    "dateReserved": "2026-07-14T10:28:12.655Z",
    "dateUpdated": "2026-07-28T16:33:31.447Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-62431",
      "date": "2026-07-30",
      "epss": "0.00375",
      "percentile": "0.30206"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-62431\",\"sourceIdentifier\":\"security@xen.org\",\"published\":\"2026-07-28T13:19:02.010\",\"lastModified\":\"2026-07-28T17:16:55.977\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"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\":[{\"source\":\"security@xen.org\",\"affectedData\":[{\"vendor\":\"Xen\",\"product\":\"Xen\",\"defaultStatus\":\"unknown\",\"versions\":[{\"version\":\"consult Xen advisory XSA-504\",\"status\":\"unknown\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-28T15:49:03.810668Z\",\"id\":\"CVE-2026-62431\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-369\"}]}],\"references\":[{\"url\":\"https://xenbits.xenproject.org/xsa/advisory-504.html\",\"source\":\"security@xen.org\"},{\"url\":\"http://www.openwall.com/lists/oss-security/2026/07/28/20\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"http://xenbits.xen.org/xsa/advisory-504.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "redhat_vex": {
      "current_release_date": "2026-07-28T18:10:47+00:00",
      "cve": "CVE-2026-62431",
      "id": "CVE-2026-62431",
      "initial_release_date": "2026-07-28T12:32:43.849000+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "xen: Xen: Denial of Service due to division by zero in Viridian STIMER handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-62431.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"http://xenbits.xen.org/xsa/advisory-504.html\"}, {\"url\": \"http://www.openwall.com/lists/oss-security/2026/07/28/20\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2026-07-28T16:33:31.447Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-62431\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-28T15:49:03.810668Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-369\", \"description\": \"CWE-369 Divide By Zero\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-28T14:37:50.672Z\"}}], \"cna\": {\"title\": \"Viridian STIMER division by zero\", \"impacts\": [{\"descriptions\": [{\"lang\": \"en\", \"value\": \"Enabling Viridian STIMERs to unprivileged HVM guests can result in a Denial\\nof Service (DoS) affecting the entire host.\"}]}], \"affected\": [{\"vendor\": \"Xen\", \"product\": \"Xen\", \"versions\": [{\"status\": \"unknown\", \"version\": \"consult Xen advisory XSA-504\"}], \"defaultStatus\": \"unknown\"}], \"datePublic\": \"2026-07-28T12:00:00.000Z\", \"references\": [{\"url\": \"https://xenbits.xenproject.org/xsa/advisory-504.html\"}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"Not enabling Viridian STIMERs for HVM guests will avoid the vulnerability.\\n\\nNote Viridian extensions are not enabled by default.\"}], \"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.\"}], \"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.\"}], \"providerMetadata\": {\"orgId\": \"23aa2041-22e1-471f-9209-9b7396fa234f\", \"shortName\": \"XEN\", \"dateUpdated\": \"2026-07-28T12:32:43.849Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-62431\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-28T16:33:31.447Z\", \"dateReserved\": \"2026-07-14T10:28:12.655Z\", \"assignerOrgId\": \"23aa2041-22e1-471f-9209-9b7396fa234f\", \"datePublished\": \"2026-07-28T12:32:43.849Z\", \"assignerShortName\": \"XEN\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.