llama.cpp versions starting at build b7492 contain a use-after-free vulnerability (CWE-416) in the vocab pointer of llama-server triggered when the --sleep-idle-seconds feature is enabled. Attackers can remotely exploit this by sending requests while the server transitions to sleep mode, leading to concurrent worker threads dereferencing a freed vocab pointer. This pointer can be reclaimed with attacker-controlled data, enabling remote code execution. The vulnerability is unauthenticated and network exploitable, with high attack complexity and partial user interaction required.

Successful exploitation allows unauthenticated remote attackers to execute arbitrary code on the affected server. This can lead to full compromise of the system running llama.cpp with the vulnerable feature enabled. The vulnerability affects server stability and security during sleep mode transitions.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, it is recommended to disable the --sleep-idle-seconds feature to prevent triggering the use-after-free condition.