vLLM is an inference and serving engine for large language models (LLMs). From 0.1.0 to before 0.19.0, a Denial of Service vulnerability exists in the vLLM OpenAI-compatible API server. Due to the lack of an upper bound validation on the n parameter in the ChatCompletionRequest and CompletionRequest Pydantic models, an unauthenticated attacker can send a single HTTP request with an astronomically large n value. This completely blocks the Python asyncio event loop and causes immediate Out-Of-Memory crashes by allocating millions of request object copies in the heap before the request even reaches the scheduling queue. This vulnerability is fixed in 0.19.0.
References
Configurations
History
07 Jul 2026, 12:16
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30 Jun 2026, 03:18
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| CWE | CWE-1284 |
20 Apr 2026, 18:30
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Vllm
Vllm vllm |
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| CPE | cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:* | |
| References | () https://github.com/vllm-project/vllm/commit/b111f8a61f100fdca08706f41f29ef3548de7380 - Patch | |
| References | () https://github.com/vllm-project/vllm/pull/37952 - Issue Tracking, Patch | |
| References | () https://github.com/vllm-project/vllm/security/advisories/GHSA-3mwp-wvh9-7528 - Patch, Vendor Advisory |
06 Apr 2026, 16:16
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Information
Published : 2026-04-06 16:16
Updated : 2026-07-15 02:20
NVD link : CVE-2026-34756
Mitre link : CVE-2026-34756
CVE.ORG link : CVE-2026-34756
JSON object : View
Products Affected
vllm
- vllm