CVE-2026-23321

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.19.0-08368-gfafda3b4b06b #22

Description The Linux kernel contains a flaw related to MPTCP (Multipath TCP) path management. A specific sequence of actions, involving setting the MPTCP subflows limit to zero, creating an MPTCP endpoint with both 'signal' and 'subflow' flags, creating a new MPTCP connection with an address addition linked to the endpoint (using the 'signal' flag but not initiating subflows with the 'subflow' flag), and then removing the endpoint, can trigger a warning indicating an issue with marking the endpoint as used. This can lead to unexpected behavior within the MPTCP subsystem.

Recommendations Update to Linux kernel version 6.19.0-08368-gfafda3b4b06b #22 or a later version to address this issue.