NULL pointer dereference in Linux kernel - CVE-2026-63876
Published: July 20, 2026
Vulnerability identifier: #VU138776
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-2026-63876
CWE-ID: CWE-476
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 null pointer dereference in the zs serial driver during serial port initialization when initializing the first serial port. A local user can trigger driver initialization to cause a denial of service.
The issue can crash the kernel during system bootstrap on affected DECstation systems.
How to mitigate CVE-2026-63876
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/237dc8c08de3cb293b6607aaee8b13b3a671e267
- https://git.kernel.org/stable/c/4dc9f1517503c883d5ce25b7ab29d177d05edc6a
- https://git.kernel.org/stable/c/6a83d5e24a84e746425cd93539130e5f7381ef47
- https://git.kernel.org/stable/c/7cac59d08a73cb866ec51a483a6f3fe0f531947c
- https://git.kernel.org/stable/c/bb2040484f90f91b717060e1a66026cc4287bcf0