Double Free in Linux kernel - CVE-2026-23394

 

Double Free in Linux kernel - CVE-2026-23394

Published: March 25, 2026


Vulnerability identifier: #VU124443
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-2026-23394
CWE-ID: CWE-415
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a race condition in the af_unix garbage collection mechanism when handling MSG_PEEK system calls. A local user can send a specially crafted sequence of system calls involving MSG_PEEK and socket closure to trigger incorrect garbage collection of active Unix domain sockets, leading to a denial of service.

The issue arises when MSG_PEEK increases a file reference count without synchronizing with garbage collection, causing the collector to incorrectly identify live sockets as dead and purge their receive queues.


Affected software

Linux kernel
Debian Linux
Ubuntu
openEuler
python3-perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
kernel-source
kernel-extra-modules
linux-fips (Ubuntu package)
linux (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux (Debian package)
linux-oracle-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)

How to mitigate CVE-2026-23394

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-extra-modules - update to 6.6.0-145.0.2.143
linux-fips (Ubuntu package) - update to 6.8.0-116.116+fips1
linux (Ubuntu package) - addressed in versions 6.8.0-117.117, 6.8.0-117.117.1, 6.8.0-117.117.1~22.04.1, 6.8.0-1041.44, 6.8.0-1054.60, 6.8.0-1055.56, 6.8.0-1055.56~22.04.1, 6.8.0-1055.58+fips1, 6.8.0-1056.60, 6.8.0-1058.61, 6.8.0-1058.61+fips1, 6.8.0-2045.46, 6.8.1-1051.52, 6.8.1-1051.52~22.04.1, 6.17.0-29.29, 6.17.0-29.29~24.04.1, 6.17.0-1013.15, 6.17.0-1013.15~24.04.1, 6.17.0-1014.14, 6.17.0-1015.15, 6.17.0-1017.17, 6.17.0-1023.23
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1024.24
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1054.57, 6.8.0-1054.57.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1056.62, 6.17.0-1015.15, 6.17.0-1015.15~24.04.1
linux (Debian package) - update to 6.12.94-1
linux-oracle-6.17 (Ubuntu package) - update to 6.17.0-1014.14~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1026.26

External References

Related Security Bulletins