CVE-2026-48746: vllm-project vllm HTTP Request/Response Smuggling
Vulnerability summary
CVE-2026-48746 is a critical (CVSS 9.1) HTTP Request/Response Smuggling vulnerability in vllm-project vllm. EPSS estimates a 1.15% chance of exploitation in the next 30 days, higher than 66.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 22-06-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · PypiEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- OSV · ChainguardEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
1.15%
Chance of exploitation in the next 30 days
Percentile
67%
Versus all other CVEs
30-day change
0.00 pp
From 1.15% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
- CWE-501Trust Boundary ViolationThe product mixes trusted and untrusted data in the same data structure or structured message.
Affected systems
Chainguard14 products
- lmcache-cuda-12.8All versions (No fix recorded)
- nemo-rl-cuda-13.0-vllmAll versions (No fix recorded)
- py3.10-vllm-cuda-12.4< 0.18.1-r4
- py3.10-vllm-cuda-12.9< 0.19.1-r1
- py3.10-vllm-cuda-13.0< 0.20.2-r1
PyPI1 product
- vllm≥ 0.3.0, < 0.22.0
Vllm1 product
- vllm≥ 0.3.0, < 0.22.0
Vllm-project1 product
- vllm≥ 0.3.0, < 0.22.0
4 vendors · 17 products
References
20 links- github.com/vllm-project/vllm/security/advisories/GHSA-94f4-hr76-p5j6X Refsource CONFIRMWEBAdvisoryThird Party Advisory
Show all 20 references
- github.com/vllm-project/vllmPACKAGE