CVE-2026-62436 (GCVE-0-2026-62436)
Vulnerability from cvelistv5
Published
2026-07-28 12:32
Modified
2026-07-28 15:17
Severity ?
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Summary
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] With the introduction of Grant Table v2 came the requirement to be able to switch between versions. Switching from v1 to v2 reduces the number of valid grant references, as a bigger shared entry structure is then needed while the shared table doesn't change size. Switching from v2 back to v1 the status frames, which are separate in v2, go away. Code holding, but intermediately dropping and then re-acquiring the grant table lock, sometimes wrongly assumes that said properties wouldn't change across the window in time where the lock is not being held. The v1 -> v2 issue is CVE-2026-62435. The v2 -> v1 issue is CVE-2026-62436.
References
Impacted products
Vendor Product Version
Xen Xen Create a notification for this product.
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              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
              "version": "3.1"
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                "id": "CVE-2026-62436",
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                "timestamp": "2026-07-28T15:16:28.153900Z",
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      ],
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      "descriptions": [
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          "value": "[This CNA information record relates to multiple CVEs; the\ntext explains which aspects/vulnerabilities correspond to which CVE.]\n\nWith the introduction of Grant Table v2 came the requirement to be able to\nswitch between versions.  Switching from v1 to v2 reduces the number of\nvalid grant references, as a bigger shared entry structure is then needed\nwhile the shared table doesn\u0027t change size.  Switching from v2 back to v1\nthe status frames, which are separate in v2, go away.\n\nCode holding, but intermediately dropping and then re-acquiring the grant\ntable lock, sometimes wrongly assumes that said properties wouldn\u0027t change\nacross the window in time where the lock is not being held.\n\nThe v1 -\u003e v2 issue is CVE-2026-62435.\n\nThe v2 -\u003e v1 issue is CVE-2026-62436."
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      "title": "grant-table: version change racing with other operations",
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        }
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    "assignerShortName": "XEN",
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    "dateReserved": "2026-07-14T10:28:12.655Z",
    "dateUpdated": "2026-07-28T15:17:33.705Z",
    "state": "PUBLISHED"
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