SB20260720396 - NULL pointer dereference in Linux kernel tty serial driver
Published: July 20, 2026
Security Bulletin ID
SB20260720396
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) NULL pointer dereference (CVE-ID: CVE-2026-63877)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 6.8 [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]
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.
Remediation
Install update from vendor's website.
References
- 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