SB20260325140 - Incomplete Blacklist to Cross-Site Scripting in Linux kernel mptcp
Published: March 25, 2026
Security Bulletin ID
SB20260325140
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) Incomplete Blacklist to Cross-Site Scripting (CVE-ID: CVE-2026-23321)
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper state management in the MPTCP subsystem when handling endpoint removal. A local user can send a specially crafted sequence of netlink commands to trigger a kernel warning and system instability.
The attacker must be able to create and remove MPTCP endpoints with specific flags and manipulate connection states, which requires access to the MPTCP netlink interface.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/05799c2f1ca5eb13d65764dda688d02021b65e06
- https://git.kernel.org/stable/c/198824ccfa64ffebd918bf99c939bd8170a4a4d8
- https://git.kernel.org/stable/c/579a752464a64cb5f9139102f0e6b90a1f595ceb
- https://git.kernel.org/stable/c/67f34ab318807989b57dfdb0f79e2d4e57018290
- https://git.kernel.org/stable/c/a64aa7db39392add5be09dffaedbf1f0ce5554df
- https://git.kernel.org/stable/c/c5c877e140e5f46023a74a51e577ce5edd0a4be7