CVE-2026-116180

Name of the Vulnerable Software and Affected Versions vLLM versions 0.8.5 through 0.30.9

Description A denial of service flaw exists where the LogprobsTensors.empty cpu() function in vllm/v1/outputs.py allocates an uninitialized int32 tensor. Additionally, the V1 model runner fails to write prompt positions reported as computed by a KV connector. A client sharing the engine can trigger an OverflowError during tokenizer decoding by sending prompt logprobs (or echo with logprobs) against a connector-cached prefix. This results in a crash of the EngineCore and the loss of all co-tenant requests.

Recommendations Update vLLM to version 0.31.0 or later.