CVE-2026-48746 — vLLM: OpenAI auth bypass

Description (CNA)

vLLM is an inference and serving engine for large language models (LLMs). From 0.3.0 until 0.22.0, a vulnerability in ASGI web servers and starlette's trust on those web servers enables an authentication bypass of the OpenAI API AuthenticationMiddleware. It allows to use the API without providing the configured VLLM_API_KEY or --api-key. This vulnerability is fixed in 0.22.0.

Affected (CNA)

Vendor / product	Versions
vllm-project / vllm	affected >= 0.3.0, < 0.22.0

CWE

CWE-444

References

ADP enrichment

CISA-ADP

No English description supplied.

https://x41-dsec.de/lab/advisories/x41-2026-002-starlette

redhat-SADP

A flaw was found in vLLM, an inference and serving engine for large language models (LLMs). This vulnerability, residing in ASGI web servers and Starlette's trust in them, allows an attacker to bypass the OpenAI API Authentication Middleware. This bypass enables unauthorized access to the API without requiring the configured VLLM_API_KEY or --api-key, leading to critical unauthorized operations.