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CVE-2026-115916EUVD-2026-110036GHSA-Q97C-P368-75C4PYSEC-2026-4347

vLLM: Out-of-vocabulary prompt token id passes input validation and triggers a CUDA device-side assert (engine crash / DoS)

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.32.0
None on Exploit-DB, Metasploit or GitHub

Summary

vLLM, an inference and serving engine for large language models, is affected. A crafted pre-tokenized prompt containing a token ID equal to the vocabulary size can slip past input validation and crash the serving engine, causing a denial of service.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Read the original description

vLLM is an inference and serving engine for large language models. Prior to 0.32.0, vllm/tokenizers/hf.py computes max_token_id with an off-by-one upper bound, allowing a pre-tokenized prompt ID equal to the vocabulary size to pass validation. For a tensor-parallel size of one and an exact multiple-of-64 vocabulary, VocabParallelEmbedding.forward does not mask that value before F.embedding uses it, causing a CUDA device-side assertion and terminating the engine. This issue is fixed in version 0.32.0.

Timeline

  1. CVE published
  2. First seen by cve.now

Affected versions

  • vllm-project vllm

    fixed in 0.32.0

  • vllmPyPI

    fixed in 0.32.0

References 4

GitHub · vllm-project/vllm