Vulnerability in Vllm-Project Vllm
CVE-2026-93840
vLLM before 0.29.0 validates allowed_token_ids against tokenizer length instead of model output logits width in SamplingParams._validate_allowed_token_ids(). Attackers can supply token IDs above the output vocabulary that pass validation, causing LogitBiasState to corrupt GPU logits state and allow concurrent requests to sample tokens outside their allowlists.
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking, patch)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-93840?
- CVE-2026-93840 is a low-severity vulnerability in Vllm-Project Vllm, classified under Improper Validation of Array Index. CVSS score: 3.7/10. Published 2026-09-18.
- How severe is CVE-2026-93840?
- Low severity. CVSS v3 base score is 3.7 out of 10.