SB20260720146 - Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel batman-adv



SB20260720146 - Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel batman-adv

Published: July 20, 2026

Security Bulletin ID SB20260720146
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) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-64091)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

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 user to cause a denial of service.

The vulnerability exists due to a race condition leading to an out-of-bounds write in batadv_tt_prepare_tvlv_local_data in the batman-adv translation table handling when generating local TT TVLV data for reported VLANs. A local user can trigger concurrent VLAN translation table entry changes to cause a denial of service.

The issue arises from a time-of-check time-of-use condition where the number of non-empty VLANs can increase after buffer sizing but before the buffer is filled.


Remediation

Install update from vendor's website.