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

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.