Unpatched Critical LMCache Flaw Lets Unauthenticated Attackers Run Code Remotely

Unpatched Critical LMCache Flaw Lets Unauthenticated Attackers Run Code Remotely Swati KhandelwalOct 07, 2026Vulnerability / Artificial Intelligence A critical vulnerability in LMCache, open-source software that speeds up large language model (LLM) servers such as vLLM, lets an attacker run code on the cache server without logging in, and no fixed version is available. The flaw is in LMCache's multiprocess mode, where the cache runs as a standalone server that LLM workers reach over the ZeroMQ messaging library. A single network message to that server can run commands as the user the LMCache process runs as. The server can be reached from another machine only when an operator sets it to listen on a routable address, rather than the localhost it…