LMCache Unauthenticated RCE Finally Patched in Version 0.5.6 (CVE-2026-105192)

Scope: LMCache (distributed key-value cache layer for the vLLM inference engine), versions 0.3.9 through 0.5.5 and the 0.5.6 release candidates

Severity: Red

We flagged CVE-2026-105192 roughly two weeks ago when it had a public proof of concept and no patch at all. That has now changed. LMCache 0.5.6, released October 15, 2026, closes the flaw, which allowed an unauthenticated attacker to send a single crafted network message to the LMCache multiprocess server and execute arbitrary code with the privileges of the LMCache process, root in most default container deployments. The server only becomes remotely reachable when an operator configures it to listen on a routable network address rather than the localhost-only default, so exposure has always depended on deployment choices rather than being universal, but any team that stood up LMCache quickly for an AI inference pipeline without reviewing that setting should check it now. Organisations running LMCache must update to version 0.5.6 immediately, and anyone who was running an exposed instance on an earlier version during the weeks this flaw lacked a fix should review logs and system state for any signs it was already abused.

The Uganda National CERT and Coordination Center (CERT.UG/CC) encourages users and administrators to review the recommendations and apply the necessary updates.