Use-after-free in Linux kernel - CVE-2026-63919
Published: July 20, 2026
Vulnerability identifier: #VU138724
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-2026-63919
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 transport-mode deferred reinjection handling in net/xfrm/xfrm_input.c when processing deferred transport reinjection callbacks that use a stored network namespace pointer. A local user can trigger deferred transport reinjection with a dangling net namespace reference to cause a denial of service.
How to mitigate CVE-2026-63919
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/2df7059a18afb7d3aee6c36cad5d371c198111d4
- https://git.kernel.org/stable/c/48ce101cd630d6745b6923b5bad8358bc4c119da
- https://git.kernel.org/stable/c/55ddfc41451f01c588089cd74957a05311b6f202
- https://git.kernel.org/stable/c/7ee59eda8820b758ed29e1cd3222359c7b97302c
- https://git.kernel.org/stable/c/8dfabcba6a943a7a02ebe1e1637c361ba96acbaa
- https://git.kernel.org/stable/c/9f67a36e91bb50d358760f381f233913fe5c09f8
- https://git.kernel.org/stable/c/9f7ebb45a83afc3216e855e57d51bb4bc9b5232e
- https://git.kernel.org/stable/c/c16f74dc1d75d0e2e7670076d5375deda110ebeb