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CVE-2026-64533

HIGH 7.8 ALL-YEARS

Published 2026-07-27 · Last modified 2026-10-19 · Linux · NVD: Received

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate lcns_follow in log_replay conversion log_replay() converts DIR_PAGE_ENTRY_32 records into DIR_PAGE_ENTRY records when replaying version 0 restart tables. During this conversion, the memmove() length is derived directly from the on-disk lcns_follow field: memmove(&dp->vcn, &dp0->vcn_low, 2 * sizeof(u64) + le32_to_cpu(dp->lcns_follow) * sizeof(u64)); check_rstbl() validates restart table structure, but does not constrain per-entry lcns_follow values relative to the entry size. A malformed filesystem image can provide an oversized lcns_follow value, causing the conversion memmove() to access memory beyond the bounds of the allocated restart table buffer. The same field is later used to bound iteration over page_lcns[], so validating lcns_follow during conversion also prevents downstream out-of-bounds access from the same malformed metadata. Compute the maximum valid lcns_follow from the already-validated restart table entry size and reject entries that exceed this bound. Reuse the existing t16/t32 scratch variables already declared in log_replay() to avoid introducing new declarations. [[email protected]: fixed the conflicts]

ELEVATED IMPACT

Severe if exploited (CVSS 7.8), but no confirmed exploitation. Patch on a normal cadence.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 3rd percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

7.8CVSS 3.1 · HIGH · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ⚠Access: Requires local access to the host
  • ✓Privileges: No account or privileges required
  • ⚠User interaction: A user must take an action (click / open a file)
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Linux

Products Linux

Weakness (CWE)

  • CWE-787: Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References and research data (JSON)

Vendor product assessments

Showing 32 of 274 vendor product statements; 242 omitted. Read the full vendor advisory.

  • kernel as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-64k-debug-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-debug-core as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug-core

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-devel-matched as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-devel-matched

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-64k-debug as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-64k-debug

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-64k-modules-extra as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-64k-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-devel as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-devel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-uki-virt-addons as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-uki-virt-addons

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel.src as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel?arch=src

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-debug as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • perf as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/perf

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-doc as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-doc

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-doc

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools-libs-devel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-cross-headers as a component of Red Hat Enterprise Linux 8 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-cross-headers

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 8 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 8 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-debug-devel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 8 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-modules-internal

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-zfcpdump-devel as a component of Red Hat Enterprise Linux 8 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-zfcpdump-devel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-64k-debug-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-64k-modules-partner as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-64k-modules-partner

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-debug-modules-core as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug-modules-core

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-64k as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-64k

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-64k-debug-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-64k-modules-internal as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-64k-modules-internal

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-debug-modules-core as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-debug-modules-core

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-rt-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools-libs-devel

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • kernel-zfcpdump-modules-extra as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-zfcpdump-modules-extra

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00
  • rv as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/rv

    Red Hat · CVE-2026-64533 · Updated 2026-07-29T06:27:37+00:00

All CVSS metrics

  • HIGH 7.8 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
  • HIGH 7.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS