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critical 9.8

CVE-2026-63800 in the critical feed json

pNFS: Fix use-after-free in pnfs_update_layout()

published 3mo ago modified 23d ago also EUVD-2026-45466

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

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

pNFS: Fix use-after-free in pnfs_update_layout()

When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields.

Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).

Patch / fix

  • Linux Linux 5.5, 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2
  • linux Debian 12 6.1.177-1
  • linux Debian 13 6.12.95-1
  • linux Debian 14 7.1.3-1

debian advisories DEBIAN-CVE-2026-63800

  • linux Ubuntu 22.04 LTS 5.15.0-194.204
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1116.123
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1117.127
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-63800

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 RHEL 9 5.14.0-687.44.1.el9_8
  • rv RHEL 9 5.14.0-687.44.1.el9_8
  • perf RHEL 9 5.14.0-687.44.1.el9_8
  • rtla RHEL 9 5.14.0-687.44.1.el9_8
  • libperf RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.44.1.el9_8

red hat advisories RHSA-2026:63129RHSA-2026:63014RHSA-2026:63013RHSA-2026:61887

  • kernel-source openSUSE Tumbleweed 7.1.4-1.1

opensuse advisories openSUSE-SU-2026:11339-1

  • kernel-rt AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel AlmaLinux 8 4.18.0-553.159.1.el8_10

almalinux advisories ALSA-2026:63013ALSA-2026:63014ALSA-2026:63129ALSA-2026:61887

  • kernel Rocky Linux 9 5.14.0-687.44.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel Rocky Linux 8 4.18.0-553.159.1.el8_10
  • kernel Rocky Linux 10 6.12.0-211.50.1.el10_2

rocky linux advisories RLSA-2026:63129RLSA-2026:63013RLSA-2026:63014RLSA-2026:61887

Is CVE-2026-63800 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-63800 updated cvss 4.7

kernel: pNFS: Fix use-after-free in pnfs_update_layout()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • 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
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.44.1.el9_8, perf 5.14.0-687.44.1.el9_8, rtla 5.14.0-687.44.1.el9_8, python3-perf 5.14.0-687.44.1.el9_8, kernel-devel-matched 5.14.0-687.44.1.el9_8, kernel-64k-devel-matched 5.14.0-687.44.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.50.1.el10_2, perf 6.12.0-211.50.1.el10_2, rtla 6.12.0-211.50.1.el10_2, python3-perf 6.12.0-211.50.1.el10_2, kernel-devel-matched 6.12.0-211.50.1.el10_2, kernel-64k-devel-matched 6.12.0-211.50.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.159.1.el8_10, kernel 4.18.0-553.159.1.el8_10, bpftool 4.18.0-553.159.1.el8_10, kernel-core 4.18.0-553.159.1.el8_10, kernel-tools 4.18.0-553.159.1.el8_10, python3-perf 4.18.0-553.159.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:63014
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.44.1.el9_8, kernel-64k 5.14.0-687.44.1.el9_8, kernel-core 5.14.0-687.44.1.el9_8, kernel-tools 5.14.0-687.44.1.el9_8, kernel-modules 5.14.0-687.44.1.el9_8, kernel-64k-core 5.14.0-687.44.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.50.1.el10_2, kernel-64k 6.12.0-211.50.1.el10_2, kernel-core 6.12.0-211.50.1.el10_2, kernel-tools 6.12.0-211.50.1.el10_2, kernel-modules 6.12.0-211.50.1.el10_2, kernel-64k-core 6.12.0-211.50.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.44.1.el9_8
    fixed: vendor fix RHSA-2026:63129
show 9 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.50.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.50.1.el10_2
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.159.1.el8_10
    fixed: vendor fix RHSA-2026:63014
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, +4 more
    fixed: vendor fix RHSA-2026:63013
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.44.1.el9_8, kernel-rt-64k 5.14.0-687.44.1.el9_8, kernel-rt-core 5.14.0-687.44.1.el9_8, kernel-rt-modules 5.14.0-687.44.1.el9_8, kernel-rt-64k-core 5.14.0-687.44.1.el9_8, kernel-rt-debug-core 5.14.0-687.44.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.50.1.el10_2, kernel-rt-64k 6.12.0-211.50.1.el10_2, kernel-rt-core 6.12.0-211.50.1.el10_2, kernel-rt-modules 6.12.0-211.50.1.el10_2, kernel-rt-64k-core 6.12.0-211.50.1.el10_2, kernel-rt-debug-core 6.12.0-211.50.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.44.1.el9_8, kernel-rt-core 5.14.0-687.44.1.el9_8, kernel-rt-modules 5.14.0-687.44.1.el9_8, kernel-rt-debug-core 5.14.0-687.44.1.el9_8, kernel-rt-modules-core 5.14.0-687.44.1.el9_8, kernel-rt-debug-modules 5.14.0-687.44.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.50.1.el10_2, kernel-rt-core 6.12.0-211.50.1.el10_2, kernel-rt-modules 6.12.0-211.50.1.el10_2, kernel-rt-debug-core 6.12.0-211.50.1.el10_2, kernel-rt-modules-core 6.12.0-211.50.1.el10_2, kernel-rt-debug-modules 6.12.0-211.50.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:61887
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules-extra 4.18.0-553.159.1.rt7.500.el8_10, +2 more
    fixed: vendor fix RHSA-2026:63013
  • 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
yes
Technical impact
total
Assessed
26d ago

Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel 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.