Medium 6.5Published Oct 26, 2026

CVE-2026-115916vLLM: Out-of-vocabulary prompt token id passes input validation and triggers a CUDA device-side assert (engine crash / DoS)

Updated under an hour ago (Oct 29, 2026, 4:30 PM ET)

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It affects vllm-project vllm and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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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.

CVSS: 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-129, CWE-193
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 26, 2026
First seen by InfoSec Signals: Oct 26, 2026

Affected products

Affected products

vllm-project vllm vllm_project:vllm (from the name)	before 0.32.0	CNA record
vllm vllm vllm:vllm	before 0.32.0	NVD

References

References

https://github.com/vllm-project/vllm/security/advisories/GHSA-q97c-p368-75c4	x-refsource-confirm, patch, vendor-advisory
https://github.com/vllm-project/vllm/pull/59491	x-refsource-misc, patch
https://github.com/vllm-project/vllm/commit/37cecc8141e2dcba9dd534897a164d4baaf27229	x-refsource-misc, patch
https://github.com/vllm-project/vllm/releases/tag/v0.32.0	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.