Use-after-free in Linux kernel - CVE-2026-53239
Published: June 26, 2026
Vulnerability identifier: #VU135530
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-2026-53239
CWE-ID: CWE-416
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 use-after-free in xfrm_policy_bysel_ctx() and inexact bin handling in the xfrm policy subsystem when processing concurrent policy deletion and hash rebuild operations. A local user can trigger a race condition to cause a denial of service.
The issue occurs because an inexact bin may be freed during a window after the policy lock is released and before pruning is performed.
How to mitigate CVE-2026-53239
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7
- https://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121c
- https://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60
- https://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0f
- https://git.kernel.org/stable/c/8fc536e9f6856230f19c7d13e71af064b6a77b22
- https://git.kernel.org/stable/c/b5316e2b8614a87d8736941972441cb47bfd4491
- https://git.kernel.org/stable/c/c4c1ea36d83bf3c4569468ca5b8b614fda1bf821
- https://git.kernel.org/stable/c/ec82ea4eb220164d854f8734ca5a35e23e577b94