A flaw was found in the server implementation of vLLM, where the handling of Jinja templates does not properly validate user-supplied input through the chat_template and chat_template_kwargs parameters. When a specially crafted template is processed, it can trigger excessive looping or recursion inside the Jinja engine, consuming large amounts of CPU and memory. This can cause the server to become unresponsive or crash, resulting in a denial-of-service (DoS) condition for applications using vLLM.
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Tue, 14 Oct 2025 12:15:00 +0000
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Description | A flaw was found in the server implementation of vLLM, where the handling of Jinja templates does not properly validate user-supplied input through the chat_template and chat_template_kwargs parameters. When a specially crafted template is processed, it can trigger excessive looping or recursion inside the Jinja engine, consuming large amounts of CPU and memory. This can cause the server to become unresponsive or crash, resulting in a denial-of-service (DoS) condition for applications using vLLM. | |
Title | vllm: vLLM OpenAI-Compatible Server Resource Exhaustion via chat_template Parameters | |
Weaknesses | CWE-400 | |
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cvssV3_1
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