SB20260720279 - Out-of-bounds write in Linux kernel typec ucsi driver



SB20260720279 - Out-of-bounds write in Linux kernel typec ucsi driver

Published: July 20, 2026

Security Bulletin ID SB20260720279
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2026-63958)

CWE-ID: CWE-787 - Out-of-bounds write

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 out-of-bounds write in ucsi_connector_change() when handling a crafted UCSI CCI notification with an invalid connector number. A local attacker can provide a bogus connector number to trigger work scheduling on memory past the end of the connector array to cause a denial of service.

Exploitation requires control of a buggy or malicious PPM, such as EC firmware or an attached UCSI controller on supported transports.


Remediation

Install update from vendor's website.