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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-115916
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-26 18:17:39 UTC
Updated2026-10-26 18:34:17 UTC
DescriptionvLLM 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.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-129 | CWE-193 | CWE-129 CWE-129: Improper Validation of Array Index | CWE-193 CWE-193: Off-by-one Error

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Vllm-project Vllm affected < 0.32.0 Not specified

References

ReferenceSourceLinkTags
github.com/vllm-project/vllm/releases/tag/v0.32.0 [email protected] github.com
github.com/vllm-project/vllm/pull/59491 [email protected] github.com
github.com/vllm-project/vllm/commit/37cecc8141e2dcba9dd534897a164d4baaf2... [email protected] github.com
github.com/vllm-project/vllm/security/advisories/GHSA-q97c-p368-75c4 [email protected] github.com
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