CVE-2026-107207

LMCache through 0.5.5 contains a missing authentication vulnerability in the multiprocess mode HTTP server that allows remote unauthenticated attackers to access management endpoints listening on all interfaces by default. Attackers can read environment credentials via GET /env and configuration via GET /config, clear caches, delete cache objects, and modify tenant quotas to evict other tenants' cached data.

LMCache through 0.5.5 contains an unauthenticated remote code execution vulnerability that allows remote attackers to execute Python code by posting scripts to the /run_script endpoint. Attackers can recover real builtins through the injected FastAPI app object, bypassing the guarded __import__, to import os and run operating system commands as the LMCache process.

LMCache multiprocess (distributed) mode opens an unauthenticated ZeroMQ ROUTER socket where workers register and share KV cache blocks. Extension code 1 is passed to DeviceIPCWrapper.Deserialize, which calls pickle.loads while the server is still decoding request arguments and before the handler runs, so a single unauthenticated ZMQ DEALER message to the transport port (default 5555) executes code as the LMCache process user.

LMCache through 0.5.5 contains a missing authentication vulnerability in the multiprocess coordinator that allows remote unauthenticated attackers to access its HTTP fleet control API listening on all interfaces by default. Attackers can register or deregister instances via /instances, overwrite quotas via /quota endpoints, inject events via /events, and enumerate /directory/keys to disrupt caching and disclose placement metadata.

LMCache up to 0.5.4 contains a vulnerability in the hex_hash_to_int16 function in lmcache/integration/vllm/utils.py, involving the use of a weak hash. The attack requires local access and high complexity, and the exploit has been published. A fix is available in version 0.5.5.