CVE-2025-68221

A logic error was found in the MPTCP (Multipath TCP) path manager in the Linux kernel. An inverted WARN_ON_ONCE condition in mptcp_pm_nl_rm_addr() causes address removal counter updates to only execute in the abnormal case (counter = 0) while normal removals are ignored. This breaks MPTCP address management.

MPTCP must be enabled and in active use for this to matter. The bug causes functional issues with multipath address management rather than memory corruption or crashes.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.