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CVE-2026-23554

CVE-2026-23554 · Use after free of paging structures in EPT

This page contains facts from public vulnerability sources. Check the original advisory before updating.

The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is dropped, so that multiple modifications done under the same locked region only issue a single flush. Freeing of paging structures however is not deferred until the flushing is done, and can result in freed pages transiently being present in cached state. Such stale entries can point to memory ranges not owned by the guest, thus allowing access to unintended memory regions.

CVSS 7.8 · High · EPSS 0.1% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • xen

    Versions
    • consult Xen advisory XSA-480: Unknown

    No fix published

  • xen Debian:12

    Versions
    • 4.17.1+2-gb773c48e36-1
    • 4.17.2+55-g0b56bed864-1
    • 4.17.2+76-ge1f9cb16e2-1
    • 4.17.2+76-ge1f9cb16e2-1~deb12u1
    • 4.17.2-1
    • 4.17.3+10-g091466ba55-1
    • 4.17.3+10-g091466ba55-1.1
    • 4.17.3+10-g091466ba55-1.1~exp1
    • 4.17.3+10-g091466ba55-1.1~exp2
    • 4.17.3+10-g091466ba55-1~deb12u1
    • 4.17.3+36-g54dacb5c02-1
    • 4.17.5+23-ga4e5191dc0-1
    • 4.17.5+23-ga4e5191dc0-1+deb12u1
    • 4.17.5+72-g01140da4e8-1
    Affected ranges
    • ECOSYSTEM: < 4.17.7-0+deb12u1

    Update to 4.17.7-0+deb12u1

  • xen Debian:13

    Versions
    • 4.20.0+68-g35cb38b222-1
    • 4.20.2+37-g61ff35323e-0+deb13u1
    • 4.20.2+37-g61ff35323e-1
    • 4.20.2+7-g1badcf5035-0+deb13u1
    • 4.20.2+7-g1badcf5035-1
    • 4.20.2+7-g1badcf5035-2
    Affected ranges
    • ECOSYSTEM: < 4.20.3+127-gc42374a105-0+deb13u1

    Update to 4.20.3+127-gc42374a105-0+deb13u1

  • xen Debian:14

    Versions
    • 4.20.0+68-g35cb38b222-1
    • 4.20.2+37-g61ff35323e-1
    • 4.20.2+7-g1badcf5035-1
    • 4.20.2+7-g1badcf5035-2
    Affected ranges
    • ECOSYSTEM: < 4.20.3+127-gc42374a105-1

    Update to 4.20.3+127-gc42374a105-1

  • xen Ubuntu:16.04:LTS

    Versions
    • 4.5.1-0ubuntu1
    • 4.5.1-0ubuntu2
    • 4.6.0-1ubuntu1
    • 4.6.0-1ubuntu2
    • 4.6.0-1ubuntu4
    • 4.6.0-1ubuntu4.1
    • 4.6.0-1ubuntu4.2
    • 4.6.0-1ubuntu4.3
    • 4.6.5-0ubuntu1
    • 4.6.5-0ubuntu1.1
    • 4.6.5-0ubuntu1.2
    • 4.6.5-0ubuntu1.4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:18.04:LTS

    Versions
    • 4.9.0-0ubuntu3
    • 4.9.0-0ubuntu4
    • 4.9.2-0ubuntu1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:20.04:LTS

    Versions
    • 4.9.2-0ubuntu2
    • 4.9.2-0ubuntu6
    • 4.9.2-0ubuntu7
    • 4.11.3+24-g14b62ab3e5-1ubuntu1
    • 4.11.3+24-g14b62ab3e5-1ubuntu2
    • 4.11.3+24-g14b62ab3e5-1ubuntu2.2
    • 4.11.3+24-g14b62ab3e5-1ubuntu2.3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:22.04:LTS

    Versions
    • 4.11.4+24-gddaaccbbab-1ubuntu2
    • 4.16.0-1~ubuntu2
    • 4.16.0-1~ubuntu2.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:24.04:LTS

    Versions
    • 4.17.2-1
    • 4.17.2+55-g0b56bed864-1
    • 4.17.2+76-ge1f9cb16e2-1
    • 4.17.2+76-ge1f9cb16e2-1ubuntu1
    • 4.17.3+10-g091466ba55-1
    • 4.17.3+10-g091466ba55-1.1ubuntu2
    • 4.17.3+10-g091466ba55-1.1ubuntu3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:25.10

    Versions
    • 4.20.0-1ubuntu1
    • 4.20.0+68-g35cb38b222-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:26.10

    Versions
    • 4.20.2+7-g1badcf5035-2build2
    • 4.20.2+37-g61ff35323e-1ubuntu1
    • 4.20.3+127-gc42374a105-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • xen Ubuntu:26.04:LTS

    Versions
    • 4.20.0+68-g35cb38b222-1
    • 4.20.2+7-g1badcf5035-2
    • 4.20.2+7-g1badcf5035-2build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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