vLLM is an inference and serving engine for large language models (LLMs). From to before 0.20.0, the extract_hidden_states speculative decoding proposer in vLLM returns a tensor with an incorrect shape after the first decode step, causing a RuntimeError that crashes the EngineCore process. The crash is triggered when any request in the batch uses sampling penalty parameters (repetition_penalty, frequency_penalty, or presence_penalty). A single request with a penalty parameter (e.g., "repetition_penalty": 1.1) is sufficient to crash the server. This vulnerability is fixed in 0.20.0.
History

Fri, 15 May 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Vllm
Vllm vllm
CPEs cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*
Vendors & Products Vllm
Vllm vllm

Tue, 12 May 2026 23:30:00 +0000

Type Values Removed Values Added
First Time appeared Vllm-project
Vllm-project vllm
Vendors & Products Vllm-project
Vllm-project vllm

Tue, 12 May 2026 20:15:00 +0000

Type Values Removed Values Added
Description vLLM is an inference and serving engine for large language models (LLMs). From to before 0.20.0, the extract_hidden_states speculative decoding proposer in vLLM returns a tensor with an incorrect shape after the first decode step, causing a RuntimeError that crashes the EngineCore process. The crash is triggered when any request in the batch uses sampling penalty parameters (repetition_penalty, frequency_penalty, or presence_penalty). A single request with a penalty parameter (e.g., "repetition_penalty": 1.1) is sufficient to crash the server. This vulnerability is fixed in 0.20.0.
Title vLLM: extract_hidden_states speculative decoding crashes server on any request with penalty parameters
Weaknesses CWE-131
CWE-704
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-15T14:46:25.695Z

Reserved: 2026-05-05T15:42:40.518Z

Link: CVE-2026-44223

cve-icon Vulnrichment

Updated: 2026-05-15T14:43:40.735Z

cve-icon NVD

Status : Modified

Published: 2026-05-12T20:16:43.293

Modified: 2026-05-15T15:16:52.560

Link: CVE-2026-44223

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-12T23:15:26Z