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OpenAdvisories
Medium · 6.5 CVE-2026-115918 EUVD-2026-110039GHSA-x567-49g5-p4cfPYSEC-2026-4349

vLLM: Responses API bypasses trust_request_chat_template for chat_template_kwargs

Published Oct 26, 2026 · Updated Oct 30, 2026 · Assigned by GitHub_M

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 products

VendorProductAffectedFixed
vllm-project vllm >= 0.16.0, < 0.32.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI vllm >= 0.16.0, < 0.32.0 0.32.0 GHSA-x567-49g5-p4cf

Advisories 1

References