CVE-2026-114049

LOW 3.7

vLLM before 0.31.0 Stale allowed_token_ids Mask via InputBatch.condense

CVSS Score

3.7

EPSS Score

0.0%

EPSS Percentile

0th

vLLM before 0.31.0 contains a cross-request mask leak in InputBatch.condense() that allows remote attackers to constrain other clients' outputs by leaving stale allowed_token_ids rows. Attackers can submit concurrent constrained generate requests, including via unauthenticated /invocations, so recycled batch slots apply their token allowlist to victims' unrestricted requests.

CWE	CWE-440
Vendor	vllm-project
Product	vllm
Published	Oct 21, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Affected Versions

vllm-project / vllm

0 < 0.31.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/vllm-project/vllm/security/advisories/GHSA-6cxc-2vcg-w5qc vulncheck.com: https://www.vulncheck.com/advisories/vllm-before-0.31.0-stale-allowed-token-ids-mask-via-inputbatch-condense

Credits

glaziermag jperezdealgaba 🔍 SunnyR