Medium 6.5Published Oct 26, 2026

CVE-2026-115911vLLM: DoS via unbounded chat_template Jinja2 rendering exhausts the renderer thread pool

Updated under an hour ago (Oct 29, 2026, 8:40 AM ET)

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Every CVE for vllm-project vllm

Exploited in the last 30 days

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.

CVSS: 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400, CWE-770, CWE-834
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 26, 2026
First seen by InfoSec Signals: Oct 26, 2026

Affected products

Affected products

vllm-project vllm vllm_project:vllm (from the name)	from 0.19.0, < 0.32.0	CNA record
vllm vllm vllm:vllm	from 0.19.0 before 0.32.0	NVD

References

References

https://github.com/vllm-project/vllm/security/advisories/GHSA-542m-9234-8gvf	x-refsource-confirm, patch, vendor-advisory
https://github.com/vllm-project/vllm/pull/50300	x-refsource-misc, patch
https://github.com/vllm-project/vllm/commit/cff08b461e086523cee8bba5bd3c66d302625134	x-refsource-misc, patch
https://github.com/vllm-project/vllm/releases/tag/v0.32.0	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.