A vulnerability described as critical has been identified in Linux Kernel up to 6.6.139/6.12.85/6.18.26/7.0.3 . This issue affects the function remove_waiter of the component rtmutex . Such manipulation leads to use after free. This vulnerability is documented as CVE-2026-43499 . The attack requires being on the local network. There is not any exploit available. Upgrading the affected component is recommended.