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 3.7 LOW

3.7^/10

CVSS v3 : LOW

V3 Legend

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/vllm-project/vllm	Product
https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/sampling_params.py#L881-L903	Product
https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/v1/worker/gpu/sample/logit_bias.py#L179-L191	Product
https://github.com/vllm-project/vllm/commit/5b0e5b69ac1a3884a6479c9537789c95263cc804	Patch
https://github.com/vllm-project/vllm/pull/49080	Issue Tracking Patch
https://www.vulncheck.com/advisories/vllm-before-0.29.0-cross-request-logits-corruption-via-allowed-token-ids	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*

History

28 Sep 2026, 18:36

Type	Values Removed	Values Added
First Time		Vllm vllm Vllm
CPE		cpe:2.3:a:vllm:vllm::::::::
References	~~() https://github.com/vllm-project/vllm -~~	() https://github.com/vllm-project/vllm - Product
References	~~() https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/sampling_params.py#L881-L903 -~~	() https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/sampling_params.py#L881-L903 - Product
References	~~() https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/v1/worker/gpu/sample/logit_bias.py#L179-L191 -~~	() https://github.com/vllm-project/vllm/blob/v0.28.0/vllm/v1/worker/gpu/sample/logit_bias.py#L179-L191 - Product
References	~~() https://github.com/vllm-project/vllm/commit/5b0e5b69ac1a3884a6479c9537789c95263cc804 -~~	() https://github.com/vllm-project/vllm/commit/5b0e5b69ac1a3884a6479c9537789c95263cc804 - Patch
References	~~() https://github.com/vllm-project/vllm/pull/49080 -~~	() https://github.com/vllm-project/vllm/pull/49080 - Issue Tracking, Patch
References	~~() https://www.vulncheck.com/advisories/vllm-before-0.29.0-cross-request-logits-corruption-via-allowed-token-ids -~~	() https://www.vulncheck.com/advisories/vllm-before-0.29.0-cross-request-logits-corruption-via-allowed-token-ids - Third Party Advisory

18 Sep 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-18 20:17

Updated : 2026-09-28 18:36

NVD link : CVE-2026-93840

Mitre link : CVE-2026-93840

CVE.ORG link : CVE-2026-93840

JSON object : View

Products Affected

vllm

vllm

CWE

CWE-129

Improper Validation of Array Index

3.7 /10