Race condition in Linux kernel - CVE-2026-63942
Published: July 20, 2026
Vulnerability identifier: #VU138712
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-2026-63942
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 parport subsystem when port and client drivers are loaded around the same time during boot. A local user can load the lp and parport_pc modules concurrently to cause a crash.
The issue occurs because client drivers can attach to ports that are not completely initialized or are being torn down.
How to mitigate CVE-2026-63942
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/15b1723c1472e802f9f7e69ae4e64f7dbf588848
- https://git.kernel.org/stable/c/290f515c5e3b3900bc2fe24f179999fd08d23bfa
- https://git.kernel.org/stable/c/51026cff1f4f3b762a0b5a07c727bd59cef45320
- https://git.kernel.org/stable/c/74d6aae1df45d3414178986be743f946988fddf6
- https://git.kernel.org/stable/c/a1e81b58da0179531bedf0b9f2811f5f992d5c4b
- https://git.kernel.org/stable/c/d16548be2ea5058227d79799e81dab61c9bca8ec
- https://git.kernel.org/stable/c/ef15ccbb3e8640a723c42ad90eaf81d66ae02017
- https://git.kernel.org/stable/c/f3378b0d7bd4605de89b083b2900788157a181cc