vLLM: DoS via unbounded chat_template Jinja2 rendering exhausts the renderer thread pool

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0031, the 24th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:07 UTC First seen by agentprime
2. 31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-542m-9234-8gvf
• OSV: GHSA-542m-9234-8gvf
• github.com/vllm-project/vllm/security/advisories/GHSA-542m-9234-8gvf
• nvd.nist.gov/vuln/detail/CVE-2026-115911
• github.com/vllm-project/vllm/pull/50300
• github.com/vllm-project/vllm/commit/cff08b461e086523cee8bba5bd3c66d302625134
• github.com/vllm-project/vllm
• github.com/vllm-project/vllm/releases/tag/v0.32.0

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.