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Fencer Vulns
high 8.4

CVE-2026-80536 json

xfs: bounds-check buffer log item's dirty bitmap

published 2026-08-26 2 mo ago modified 2026-10-16 23 d ago also EUVD-2026-66451

cvss
8.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

xfs: bounds-check buffer log item's dirty bitmap

xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item:

memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT), item->ri_buf[i].iov_base, nbits << XFS_BLF_SHIFT);

The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels. A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere.

Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error.

Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it.

Patch / fix

  • Linux Linux 5.10.267, 5.15.218, 6.1.185, 6.6.154, 6.12.106, 6.18.46, 7.1.10, 7.2
  • linux Debian 12 6.1.187-1
  • linux Debian 13 6.12.107-1
  • linux Debian 14 7.1.10-1
  • linux-6.12 Debian 12 6.12.107-1~deb12u1

debian advisories DEBIAN-CVE-2026-80536

  • linux Ubuntu 22.04 LTS 5.15.0-202.212
  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1115.121
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1113.117

ubuntu advisories UBUNTU-CVE-2026-80536

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.60.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.60.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.60.1.el9_8

almalinux advisories ALSA-2026:87805ALSA-2026:88477ALSA-2026:87374ALSA-2026:87375

  • kernel Rocky Linux 10 6.12.0-211.68.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.60.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.177.1.rt7.518.el8_10
  • kernel Rocky Linux 8 4.18.0-553.177.1.el8_10

rocky linux advisories RLSA-2026:88477RLSA-2026:87805RLSA-2026:87374RLSA-2026:87375

  • kernel Azure Linux 3.0 6.6.157.1-1

azure linux advisories AZL-97851

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-80536 updated cvss 7.8

kernel: xfs: bounds-check buffer log item's dirty bitmap

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.60.1.el9_8, perf 5.14.0-687.60.1.el9_8, rtla 5.14.0-687.60.1.el9_8, python3-perf 5.14.0-687.60.1.el9_8, kernel-devel-matched 5.14.0-687.60.1.el9_8, kernel-64k-devel-matched 5.14.0-687.60.1.el9_8, +7 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.68.1.el10_2, perf 6.12.0-211.68.1.el10_2, rtla 6.12.0-211.68.1.el10_2, python3-perf 6.12.0-211.68.1.el10_2, kernel-devel-matched 6.12.0-211.68.1.el10_2, kernel-64k-devel-matched 6.12.0-211.68.1.el10_2, +7 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.177.1.el8_10, kernel 4.18.0-553.177.1.el8_10, bpftool 4.18.0-553.177.1.el8_10, kernel-core 4.18.0-553.177.1.el8_10, kernel-tools 4.18.0-553.177.1.el8_10, python3-perf 4.18.0-553.177.1.el8_10, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87375
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.60.1.el9_8, kernel-64k 5.14.0-687.60.1.el9_8, kernel-core 5.14.0-687.60.1.el9_8, kernel-tools 5.14.0-687.60.1.el9_8, kernel-modules 5.14.0-687.60.1.el9_8, kernel-64k-core 5.14.0-687.60.1.el9_8, +27 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.68.1.el10_2, kernel-64k 6.12.0-211.68.1.el10_2, kernel-core 6.12.0-211.68.1.el10_2, kernel-tools 6.12.0-211.68.1.el10_2, kernel-modules 6.12.0-211.68.1.el10_2, kernel-64k-core 6.12.0-211.68.1.el10_2, +28 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.60.1.el9_8
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
show 10 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.177.1.el8_10
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87375
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87374
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-64k 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-64k-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, +14 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-64k 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-64k-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, +14 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, kernel-rt-modules-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-modules 5.14.0-687.60.1.el9_8, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, kernel-rt-modules-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-modules 6.12.0-211.68.1.el10_2, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules-extra 4.18.0-553.177.1.rt7.518.el8_10, +2 more
    fixed: vendor fix “To mitigate this issue, prevent module xfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87374
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.4 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.