Memory leak in Linux kernel - CVE-2026-53397

Vulnerability identifier: #VU138875

CSH Severity: Low

CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53397

CWE-ID: CWE-401

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to a memory leak in the nfsd SETACL request decoding and release handling when processing crafted NFS ACL SETACL requests. A remote user can send a specially crafted SETACL request that triggers a decode failure after partial ACL allocation to cause a denial of service.

The leaked posix_acl object remains allocated for the lifetime of the server.

Linux kernel
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
openEuler
Ubuntu
kernel (Red Hat package)
kernel-rt (Red Hat package)
bpftool
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-source
kernel-headers
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
kernel
kernel-tools
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - addressed in versions 4.18.0-553.159.1.el8_10, 6.12.0-211.50.1.el10_2
kernel-rt (Red Hat package) - update to 4.18.0-553.159.1.rt7.500.el8_10
bpftool - update to 5.10.0-326.0.0.227
python3-perf-debuginfo - update to 5.10.0-326.0.0.227
python3-perf - update to 5.10.0-326.0.0.227
perf-debuginfo - update to 5.10.0-326.0.0.227
perf - update to 5.10.0-326.0.0.227
kernel-tools-devel - update to 5.10.0-326.0.0.227
kernel-tools-debuginfo - update to 5.10.0-326.0.0.227
kernel-source - update to 5.10.0-326.0.0.227
kernel-headers - update to 5.10.0-326.0.0.227
kernel-devel - update to 5.10.0-326.0.0.227
kernel-debugsource - update to 5.10.0-326.0.0.227
kernel-debuginfo - update to 5.10.0-326.0.0.227
bpftool-debuginfo - update to 5.10.0-326.0.0.227
kernel - update to 5.10.0-326.0.0.227
kernel-tools - update to 5.10.0-326.0.0.227
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

• https://git.kernel.org/stable/c/0853ac544c590880d797b04daa33fcb72b6be0e1
• https://git.kernel.org/stable/c/136b416593f1349cf6f72c8e3d18f0f204ee8545
• https://git.kernel.org/stable/c/1e96239fddcefacf6afe6c498357be68eacbcabc
• https://git.kernel.org/stable/c/887f92ceccf3eacd5f2402db21254d66372fae00
• https://git.kernel.org/stable/c/a5b42c1e4ff2befaa6b96f7cbf32174751eba083
• https://git.kernel.org/stable/c/b2eb1ffd511d1b3c3e21122f97cbbccea411e277
• https://git.kernel.org/stable/c/b94c4be77682aab06d65ca7296149e3bcfb37353
• https://git.kernel.org/stable/c/bd69a825485168ef74e815ecb286754b570fdcc7

• Memory leak in Linux kernel nfsd
• openEuler 22.03 LTS SP4 update for kernel
• Red Hat Enterprise Linux 10 update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0