vLLM is an inference and serving engine for large language models. From 0.19.0 until 0.32.0, authenticated callers can supply a request chat template when no server-side --chat-template is configured, or a malicious model repository can provide a template that is compiled and rendered by tokenizer.apply_chat_template() without a wall-clock timeout, output-size limit, or iteration bound. Rendering runs in a ThreadPoolExecutor with one worker by default, so a nonterminating render can block /v1/responses and other chat-template users after the request ends, while an output-expanding render can exhaust server memory. Harmony models are not affected because they do not use this Jinja path. This issue is fixed in version 0.32.0.
Metrics
Affected Vendors & Products
References
History
Fri, 30 Oct 2026 15:30:00 +0000
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ssvc
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Wed, 28 Oct 2026 15:45:00 +0000
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| CPEs | cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:* |
Tue, 27 Oct 2026 12:30:00 +0000
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threat_severity
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threat_severity
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Mon, 26 Oct 2026 18:45:00 +0000
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| First Time appeared |
Vllm
Vllm vllm Vllm-project Vllm-project vllm |
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| Vendors & Products |
Vllm
Vllm vllm Vllm-project Vllm-project vllm |
Mon, 26 Oct 2026 17:00:00 +0000
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| Description | vLLM is an inference and serving engine for large language models. From 0.19.0 until 0.32.0, authenticated callers can supply a request chat template when no server-side --chat-template is configured, or a malicious model repository can provide a template that is compiled and rendered by tokenizer.apply_chat_template() without a wall-clock timeout, output-size limit, or iteration bound. Rendering runs in a ThreadPoolExecutor with one worker by default, so a nonterminating render can block /v1/responses and other chat-template users after the request ends, while an output-expanding render can exhaust server memory. Harmony models are not affected because they do not use this Jinja path. This issue is fixed in version 0.32.0. | |
| Title | vLLM: DoS via unbounded chat_template Jinja2 rendering exhausts the renderer thread pool | |
| Weaknesses | CWE-400 CWE-770 CWE-834 |
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| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-10-26T16:47:59.377Z
Updated: 2026-10-30T14:20:51.484Z
Reserved: 2026-10-23T20:21:45.107Z
Link: CVE-2026-115911
Updated: 2026-10-30T14:20:46.051Z
Status : Analyzed
Published: 2026-10-26T17:17:18.753
Modified: 2026-10-30T15:16:45.860
Link: CVE-2026-115911