Use-after-free in Linux kernel - CVE-2026-63911
Published: July 20, 2026
Vulnerability identifier: #VU138747
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-2026-63911
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 use-after-free in the iptfs state cloning logic in net/xfrm/xfrm_iptfs.c when destroying a cloned security association after a failed state migration. A local user can trigger state migration failure and queued packet handling to cause a denial of service.
The issue can involve shared cloned runtime objects, including queue, timer, lock, and reassembly or reorder state copied from the original security association.
How to mitigate CVE-2026-63911
Install security update from vendor's repository.