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Fencer Vulns
high 7.5

CVE-2026-53397 json

nfsd: fix posix_acl leak on SETACL decode failure

published 2026-07-19 3 mo ago modified 2026-10-19 20 d ago also EUVD-2026-45519

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

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

nfsd: fix posix_acl leak on SETACL decode failure

nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling.

ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure:

svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */

The orphaned posix_acl is leaked for the lifetime of the server.

Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures.

Patch / fix

  • Linux Linux 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-2026-53397

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • 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 5.15.0-1117.124
  • 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 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-53397

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-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.78.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.78.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.78.1

suse advisories SUSE-SU-2026:3810-1SUSE-SU-2026:3790-1SUSE-SU-2026:23244-1SUSE-SU-2026:23241-1SUSE-SU-2026:23194-1SUSE-SU-2026:23193-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.37.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.37.1

opensuse advisories openSUSE-SU-2026:21555-1openSUSE-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

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-2026-53397 updated cvss 7.0

kernel: nfsd: fix posix_acl leak on SETACL decode failure

  • 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 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: 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
  • 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
show 7 more
  • 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 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
partial
Assessed
23 d ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
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.