CVE-2026-23558 (GCVE-0-2026-23558)
Vulnerability from cvelistv5
Published
2026-05-19 12:49
Modified
2026-05-20 03:55
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.
References
Impacted products
Vendor Product Version
Xen Xen Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-05-19T13:06:51.044Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/28/13"
          },
          {
            "url": "http://xenbits.xen.org/xsa/advisory-486.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 7.8,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "LOW",
              "scope": "CHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-23558",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-19T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-362",
                "description": "CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization (\u0027Race Condition\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-20T03:55:35.327Z",
          "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-486"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "All Xen versions from 4.0 onwards are affected.  Xen versions 3.4 and\nolder are not affected.\n\nOnly x86 HVM and PVH guests permitted to use grant table version 2\ninterfaces can leverage this vulnerability.  x86 PV guests cannot\nleverage this vulnerability.  On Arm, grant table v2 use is explicitly\nunsupported."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "This issue was discovered by Claude Opus 4.6 and diagnosed as a security\nissue by Rafal Wojtczuk."
        }
      ],
      "datePublic": "2026-04-28T12:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "The adjustments made for XSA-379 as well as those subsequently becoming\nXSA-387 still left a race window, when a HVM or PVH guest does a grant\ntable version change from v2 to v1 in parallel with mapping the status\npage(s) via XENMEM_add_to_physmap.  Some of the status pages may then be\nfreed while mappings of them would still be inserted into the guest\u0027s\nsecondary (P2M) page tables."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "Privilege escalation, information leaks, and Denial of Service (DoS) up\nto affecting the entire host cannot be excluded."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-19T12:49:54.652Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-486.html"
        }
      ],
      "title": "grant table v2 race in status page mapping",
      "workarounds": [
        {
          "lang": "en",
          "value": "Using the \"gnttab=max-ver:1\" hypervisor command line option will avoid\nthe vulnerability.\n\nUsing the \"max_grant_version=1\" guest configuration option for HVM and PVH\nguests will also avoid the vulnerability."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2026-23558",
    "datePublished": "2026-05-19T12:49:54.652Z",
    "dateReserved": "2026-01-14T13:07:36.961Z",
    "dateUpdated": "2026-05-20T03:55:35.327Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.