NULL pointer dereference in Linux kernel - CVE-2026-63877
Published: July 20, 2026
Vulnerability identifier: #VU138777
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-2026-63877
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 attacker to cause a denial of service.
The vulnerability exists due to a null pointer dereference in the dz serial driver when initializing the first serial port. A local attacker can trigger serial port initialization to cause a denial of service.
The crash occurs because a pointer derived from a null parent-device pointer is dereferenced during early system bootstrap.
How to mitigate CVE-2026-63877
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/2ff0401ffddaccc85f758c8259912d686d052b31
- https://git.kernel.org/stable/c/5c9fb95c8d6430d11dbb7b44fbe23222585cda86
- https://git.kernel.org/stable/c/5d7a49d60b8fda66da60e240fd7315232fa1754f
- https://git.kernel.org/stable/c/6f59646229490a93cda950017ad4bdfbfe770a1d
- https://git.kernel.org/stable/c/c9e78361fe92fb64662fc3c8f34e2cdbb8c25bc6