SB2026040316 - Use-after-free in Linux kernel sched
Published: April 3, 2026
Security Bulletin ID
SB2026040316
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) Use-after-free (CVE-ID: CVE-2026-23413)
The vulnerability allows a local attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the clsact qdisc when handling init and destroy rollback after a replacement failure. A local attacker can trigger a replacement failure during clsact initialization to cause a denial of service.
The issue occurs because ingress may be initialized before egress initialization fails, after which destroy logic can operate on stale state from the previous clsact instance.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/0509b762bc5e8ea7b8391130730c6d8502fc6e69
- https://git.kernel.org/stable/c/37bef86e5428d59f70a4da82b80f9a8f252fecbe
- https://git.kernel.org/stable/c/4c9af67f99aa3e51b522c54968ab3ac8272be41c
- https://git.kernel.org/stable/c/a0671125d4f55e1e98d9bde8a0b671941987e208
- https://git.kernel.org/stable/c/a73d95b57bf9faebdfed591bcb7ed9292062a84c