Vulnerability · Published Oct 26, 2026 · Assigned by GitHub_M
CVE-2026-115918vLLM: Responses API bypasses trust_request_chat_template for chat_template_kwargs
Medium 6.5
In plain English
A medium-severity uncontrolled resource consumption in vllm from vllm-project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
vLLM is an inference and serving engine for large language models. From 0.16.0 until 0.32.0, the /v1/responses endpoint allows an authenticated caller to place an attacker-controlled template in chat_template_kwargs[chat_template] when no server template is configured. ChatParams.get_apply_chat_template_kwargs() preserves that value without enforcing trust_request_chat_template, so the request can bypass the intended trust policy and cause CPU or memory exhaustion through Jinja rendering. This issue is fixed in version 0.32.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vllm | 0.32.0 | GHSA-x567-49g5-p4cf |
| PyPI | vllm | 0.32.0 | PYSEC-2026-4349 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| vllm-project | vllm | >= 0.16.0, < 0.32.0 |
Weakness: CWE-400, CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/vllm-project/vllm/security/advisories/GHSA-x567-49g5-p4cf x_refsource_CONFIRM
- https://github.com/vllm-project/vllm/pull/50300 x_refsource_MISC
- https://github.com/vllm-project/vllm/commit/cff08b461e086523cee8bba5bd3c66d302625134 x_refsource_MISC
- https://github.com/vllm-project/vllm/releases/tag/v0.32.0 x_refsource_MISC