SB2026041419 - Improper input validation in Linux kernel bridge
Published: April 14, 2026
Security Bulletin ID
SB2026041419
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 security vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-31420)
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper input validation in br_mrp_start_test(), br_mrp_start_in_test(), and br_mrp_start_in_test_parse() when processing user-supplied netlink attributes. A local user can supply a zero interval value to cause a denial of service.
A zero interval causes delayed work to be rescheduled with no delay, creating a tight loop that allocates and transmits MRP test frames until system memory is exhausted and the kernel panics via OOM deadlock.
Remediation
Install update from vendor's website.