Bug 2401761 (CVE-2025-61620)

Summary: CVE-2025-61620 vllm: vLLM OpenAI-Compatible Server Resource Exhaustion via chat_template Parameters
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: alinfoot, bbrownin, dtrifiro, jkoehler, lphiri, rbryant, security-response-team, weaton
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2025-10-06 06:05:07 UTC
Resource-Exhaustion (DoS) via chat_template / chat_template_kwargs. Attackers can craft malicious templates or arguments that consume excessive memory or CPU resources. This may lead to denial-of-service (DoS), making the vLLM OpenAI-Compatible Server unresponsive.