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

Status: published. Published: 2026-10-26. Updated: 2026-11-02.

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.

## Remediation

- fix: vllm (PyPI): OSV reports a fixed version 0.32.0. Check the advisory for supported release branches. (source: OSV GHSA-q97c-p368-75c4) — https://github.com/advisories/GHSA-q97c-p368-75c4

## Affected products and versions

- vllm-project / vllm: < 0.32.0 (affected). Source: CNA: GitHub_M
-  / vllm (vllm): 0.0.1 (affected, PyPI); 0.1.0 (affected, PyPI); 0.1.1 (affected, PyPI); 0.1.2 (affected, PyPI); 0.1.3 (affected, PyPI); 0.1.4 (affected, PyPI); 0.1.5 (affected, PyPI); 0.1.6 (affected, PyPI); 0.1.7 (affected, PyPI); 0.10.0 (affected, PyPI); 0.10.1 (affected, PyPI); 0.10.1.1 (affected, PyPI); 0.10.2 (affected, PyPI); 0.11.0 (affected, PyPI); 0.11.1 (affected, PyPI); 0.11.2 (affected, PyPI); 0.12.0 (affected, PyPI); 0.13.0 (affected, PyPI); 0.14.0 (affected, PyPI); 0.14.1 (affected, PyPI); 0.15.0 (affected, PyPI); 0.15.1 (affected, PyPI); 0.16.0 (affected, PyPI); 0.17.0 (affected, PyPI); 0.17.1 (affected, PyPI); 0.18.0 (affected, PyPI); 0.18.1 (affected, PyPI); 0.19.0 (affected, PyPI); 0.19.1 (affected, PyPI); 0.2.0 (affected, PyPI); 0.2.1 (affected, PyPI); 0.2.1.post1 (affected, PyPI); 0.2.2 (affected, PyPI); 0.2.3 (affected, PyPI); 0.2.4 (affected, PyPI); 0.2.5 (affected, PyPI); 0.2.6 (affected, PyPI); 0.2.7 (affected, PyPI); 0.20.0 (affected, PyPI); 0.20.1 (affected, PyPI); 0.20.2 (affected, PyPI); 0.21.0 (affected, PyPI); 0.22.0 (affected, PyPI); 0.22.1 (affected, PyPI); 0.23.0 (affected, PyPI); 0.24.0 (affected, PyPI); 0.25.0 (affected, PyPI); 0.25.1 (affected, PyPI); 0.26.0 (affected, PyPI); 0.27.0 (affected, PyPI); 0.27.1 (affected, PyPI); 0.28.0 (affected, PyPI); 0.29.0 (affected, PyPI); 0.3.0 (affected, PyPI); 0.3.1 (affected, PyPI); 0.3.2 (affected, PyPI); 0.3.3 (affected, PyPI); 0.30.0 (affected, PyPI); 0.31.0 (affected, PyPI); 0.4.0 (affected, PyPI); 0.4.0.post1 (affected, PyPI); 0.4.1 (affected, PyPI); 0.4.2 (affected, PyPI); 0.4.3 (affected, PyPI); 0.5.0 (affected, PyPI); 0.5.0.post1 (affected, PyPI); 0.5.1 (affected, PyPI); 0.5.2 (affected, PyPI); 0.5.3 (affected, PyPI); 0.5.3.post1 (affected, PyPI); 0.5.4 (affected, PyPI); 0.5.5 (affected, PyPI); 0.6.0 (affected, PyPI); 0.6.1 (affected, PyPI); 0.6.1.post1 (affected, PyPI); 0.6.1.post2 (affected, PyPI); 0.6.2 (affected, PyPI); 0.6.3 (affected, PyPI); 0.6.3.post1 (affected, PyPI); 0.6.4 (affected, PyPI); 0.6.4.post1 (affected, PyPI); 0.6.5 (affected, PyPI); 0.6.6 (affected, PyPI); 0.6.6.post1 (affected, PyPI); 0.7.0 (affected, PyPI); 0.7.1 (affected, PyPI); 0.7.2 (affected, PyPI); 0.7.3 (affected, PyPI); 0.8.0 (affected, PyPI); 0.8.1 (affected, PyPI); 0.8.2 (affected, PyPI); 0.8.3 (affected, PyPI); 0.8.4 (affected, PyPI); 0.8.5 (affected, PyPI); 0.8.5.post1 (affected, PyPI); 0.9.0 (affected, PyPI); 0.9.0.1 (affected, PyPI); 0.9.1 (affected, PyPI); 0.9.2 (affected, PyPI); Ecosystem version events: introduced 0; fixed 0.32.0. Source: OSV GHSA-q97c-p368-75c4

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.31% as of 2026-11-02; percentile 24.08%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-129, CWE-193

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/vllm-project/vllm/security/advisories/GHSA-q97c-p368-75c4 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/vllm-project/vllm/pull/59491 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/vllm-project/vllm/commit/37cecc8141e2dcba9dd534897a164d4baaf27229 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/vllm-project/vllm/releases/tag/v0.32.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/advisories/GHSA-q97c-p368-75c4 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-q97c-p368-75c4 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-115916; retrieved 2026-11-02; source updated 2026-11-02

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-q97c-p368-75c4; retrieved 2026-11-02; source updated 2026-10-29

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-115916; retrieved 2026-11-02; source updated Not reported

Revision: 16dfc157c420d48a711d2260d744ad301117e1fba65cef4e9f77a5e8a10a1959

Canonical: https://y2.dev/cve/CVE-2026-115916

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