Race condition in Linux kernel - CVE-2026-23440
Published: April 6, 2026
Vulnerability identifier: #VU124931
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-23440
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in the net/mlx5e IPSec ESN update handling path when processing ESN wrap events in IPSec full offload mode. A local user can trigger duplicate ESN update handling to cause a denial of service.
Processing the same event twice can incorrectly increment the ESN high-order bits and program invalid ESN state into hardware, resulting in anti-replay failures and a complete halt of IPSec traffic.
How to mitigate CVE-2026-23440
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/2051c709dce92da3550040aa7949cd5a9c89b14e
- https://git.kernel.org/stable/c/3dffc083292e6872787bd7e34b957627622f9af4
- https://git.kernel.org/stable/c/8d625c15471fb8780125eaef682983a96af77bdc
- https://git.kernel.org/stable/c/96c9c25b74686ac2de15921c9ad30c5ef13af8cd
- https://git.kernel.org/stable/c/beb6e2e5976a128b0cccf10d158124422210c5ef