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OpenAdvisories
Medium · 6.5 CVE-2026-115916 EUVD-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 Oct 26, 2026 · Updated Nov 2, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
vllm-project vllm < 0.32.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI vllm < 0.32.0 0.32.0 GHSA-q97c-p368-75c4

Advisories 1

References