vLLM versions prior to 0.31.0 use a client‑supplied multimodal UUID verbatim as a cache identity without performing consistency checks. This flaw allows an unauthenticated attacker to supply forged UUIDs that cause a token‑placeholder mismatch, leading the engine to crash and terminate the entire serving instance. The resulting denial of service renders the application unavailable until a restart restores operation.

The affected product is vLLM from the vllm‑project. All releases before 0.31.0 are vulnerable; versions 0.31.0 and newer have the issue fixed.

The CVSS score of 7.1 indicates a high severity. The EPSS score is less than 1%, suggesting a low probability of exploitation in the wild, and the vulnerability is not listed in CISA’s KEV catalog. The most likely attack vector is a remote, unauthenticated submission of crafted multimodal UUIDs that desynchronize the P0/P1 processor caches, triggering a fatal crash.