CVE-2026-34756 (GCVE-0-2026-34756)
Vulnerability from cvelistv5
Published
2026-04-06 15:40
Modified
2026-04-07 14:17
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
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.
Impacted products
Vendor Product Version
vllm-project vllm Version: >= 0.1.0, < 0.19.0
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Show details on NVD website


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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