Tornado: Quadratic DoS via Crafted Multipart Parameters

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 0.0057, the 47th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:42 UTC First seen by agentprime
2. 31 Oct 2026, 14:42 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-jhmp-mqwm-3gq8
• OSV: GHSA-jhmp-mqwm-3gq8
• github.com/tornadoweb/tornado/security/advisories/GHSA-jhmp-mqwm-3gq8
• nvd.nist.gov/vuln/detail/CVE-2025-67726
• github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd
• github.com/pypa/advisory-database/tree/main/vulns/tornado/PYSEC-2025-267.yaml
• github.com/tornadoweb/tornado
• github.com/tornadoweb/tornado/releases/tag/v6.5.3

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.