Improper input validation in Linux kernel - CVE-2026-63852
Published: July 20, 2026
Vulnerability identifier: #VU138793
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-2026-63852
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 amdgpu VCN v4.0.3 encoder ring handling when processing command submissions with user fences. A local user can submit a crafted command stream with a user fence to cause a denial of service.
The issue affects VCN v4.0.3 encoder ring behavior because 64-bit user fence writes are not supported.
How to mitigate CVE-2026-63852
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0177ac6141c8857130cf365369c74dee7b6b1f7f
- https://git.kernel.org/stable/c/387b7c7667bd5c53549350ddad866d2fcf75a529
- https://git.kernel.org/stable/c/4532b52b34e4e4310386e6fdf6a643368599f522
- https://git.kernel.org/stable/c/9076a83e5adefd10dc5c967c7b8bde601c4c512a
- https://git.kernel.org/stable/c/c12a5d35033c0640c57c10d7111c010c7b9c2c8e