Cross-Request Logits Corruption in vLLM by the vLLM Project

CVE-2026-93989

What is CVE-2026-93989?

The vLLM project, in versions up to 0.29.0, contains a vulnerability where the system fails to adequately validate bad_words token indices against the output width of the model's generation process. This flaw allows attackers to input out-of-bounds token indices, leading to corruption of logits memory for concurrent requests. Consequently, it can cause different in-flight HTTP requests to return incorrect tokens, potentially compromising the integrity of data and responses.

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