SB2026041323 - Always-Incorrect Control Flow Implementation in Linux kernel bpf
Published: April 13, 2026
Security Bulletin ID
SB2026041323
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-31413)
The vulnerability allows a local user to access out-of-bounds map memory.
The vulnerability exists due to improper handling of scalar state forking in maybe_fork_scalars() when processing BPF_OR operations with a constant source operand. A local user can execute a crafted BPF program to access out-of-bounds map memory.
The issue is caused by a verifier/runtime divergence when the destination register has a signed range of [-1, 0].
Remediation
Install update from vendor's website.