SB2026072839 - Improper input validation in Linux kernel bridge



SB2026072839 - Improper input validation in Linux kernel bridge

Published: July 28, 2026

Security Bulletin ID SB2026072839
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) Improper input validation (CVE-ID: CVE-2026-64537)

CWE-ID: CWE-20 - Improper input validation

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 improper input validation in the bridge cfm ccm transmission logic when configuring an invalid ccm interval. A local user can set an invalid expiration interval to trigger a tight workqueue loop and exhaust memory to cause a denial of service.

The issue can result in immediate re-arming of delayed work and repeated skb allocations until out-of-memory conditions occur.


Remediation

Install update from vendor's website.