Improper input validation in Linux kernel - CVE-2026-63855
Published: July 20, 2026
Vulnerability identifier: #VU138796
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-2026-63855
CWE-ID: CWE-20
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 improper input validation in the VCN v2.5 encoder and decoder rings when processing command submission requests with user fences. A local user can submit a crafted command submission with a user fence to cause a denial of service.
How to mitigate CVE-2026-63855
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/2c6fb056567efb49f8674108b86088a1cfaa86d0
- https://git.kernel.org/stable/c/4f317863a3ab212a027d8c8c3cc3af4e3fb95704
- https://git.kernel.org/stable/c/5a3c6f76cab164a5d803084908d7050f649ab7f9
- https://git.kernel.org/stable/c/602d4c5872b25ddd4d82fb2025efb9a05b187bb3
- https://git.kernel.org/stable/c/8f0ea4524dc71c6c9ec97f2711f46e12f624140f