Resource exhaustion in Vllm-Project Vllm
CVE-2026-115911
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Vllm-Project Vllm — versions >= 0.19.0, < 0.32.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-115911?
- CVE-2026-115911 is a medium-severity vulnerability in Vllm-Project Vllm, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-10-26.
- How severe is CVE-2026-115911?
- Medium severity. CVSS v3 base score is 6.5 out of 10.