SB20260720343 - Uncontrolled Recursion in Linux kernel thunderbolt driver



SB20260720343 - Uncontrolled Recursion in Linux kernel thunderbolt driver

Published: July 20, 2026

Security Bulletin ID SB20260720343
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Adjecent network
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Uncontrolled Recursion (CVE-ID: CVE-2026-63891)

CWE-ID: CWE-674 - Uncontrolled Recursion

CVSSv4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to uncontrolled recursion in __tb_property_parse_dir() in the thunderbolt property parser when processing a crafted PROPERTIES_REQUEST control-plane exchange containing chained DIRECTORY entries with a back-reference loop. A remote attacker can send crafted XDomain property data to cause a denial of service.

The issue can be triggered by an untrusted XDomain peer such as a cable, dock, in-line inspector, or adjacent host.


Remediation

Install update from vendor's website.