Use-after-free in Linux kernel - CVE-2026-43091
Published: May 7, 2026
Vulnerability identifier: #VU130668
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-2026-43091
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_bydst hash tables during network namespace teardown when concurrent RCU-protected policy lookups are performed. A local user can trigger network namespace teardown while the tables are still being accessed to cause a denial of service.
The issue occurs because the memory can be freed before an RCU grace period has elapsed.
How to mitigate CVE-2026-43091
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446
- https://git.kernel.org/stable/c/33a3149dd81a1e2f52b80ee1e0fc380b39f3d028
- https://git.kernel.org/stable/c/3733fce2871c9bca9dd18a1a23b1432ea215a094
- https://git.kernel.org/stable/c/438b1f668ad58f46ce699bb48e4698a7839e3f9e
- https://git.kernel.org/stable/c/b66920a3348c0f63ba18365248fa21fbf0b3a937