vLLM: extract_hidden_states speculative decoding crashes server on any request with penalty parameters (vllm-project vllm)

CVE-2026-44223
MEDIUM 6.5

At a glance

Source
NVD
EPSS
EPSS 0.37 % Β· percentile 30 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Modified

Description

vLLM is an inference and serving engine for large language models (LLMs). From 0.18.0 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.

Weaknesses (CWE)

  • CWE-131 β€” Incorrect Calculation of Buffer Size
  • CWE-704 β€” Incorrect Type Conversion or Cast

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HGitHub_M
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD Β· security-advisories@github.com (Secondary)

Advisories

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
vllm-project Β· vllmaffected >= 0.18.0, < 0.20.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST β€” attribution requested
ENISA EUVDENISA β€” reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain β€” this product uses data from the NVD API but is not endorsed or certified by the NVD