Use-after-free in Linux kernel - CVE-2026-52991

Vulnerability identifier: #VU135393

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-52991

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to a use-after-free in pressure_write() in kernel/cgroup/cgroup.c when handling a write to a pressure cgroup file during concurrent cgroup file release. A local user can write crafted pressure data while racing cgroup file release to cause a denial of service.

The issue occurs because the of->priv pointer may be freed concurrently and later dereferenced.

Linux kernel
openEuler
Ubuntu
bpftool
kernel
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-tools
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
python3-perf-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
python3-perf - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
perf-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
perf - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools-devel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-source - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-headers - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-devel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-debugsource - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
bpftool-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9

• https://git.kernel.org/stable/c/03dc070fa0fc3cb4068693f468ccd5f8a7e58282
• https://git.kernel.org/stable/c/a5b98009f16d8a5fb4a8ff9a193f5735515c38fa
• https://git.kernel.org/stable/c/d4352c0709bfd38c752fccbde7fd72a82ac78f23

• Use-after-free in Linux kernel cgroup
• openEuler 22.03 LTS SP4 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• openEuler 24.03 LTS SP1 update for kernel