What is CVE-2025-67725?

CVE-2025-67725 is a high-severity vulnerability in Tornadoweb Tornado, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-12-12.

How severe is CVE-2025-67725?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Tornadoweb Tornado

CVE-2025-67725

Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server's event loop for an extended period, caused by the HTTPHeaders.add method. T…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.002 (43.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Tornadoweb Tornado — versions < 6.5.3

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

https://github.com/tornadoweb/tornado/security/advisories/GHSA-c98p-7wgm-6p64 (x_refsource_CONFIRM)
https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd (x_refsource_MISC)
https://github.com/tornadoweb/tornado/releases/tag/v6.5.3 (x_refsource_MISC)

Frequently asked questions

What is CVE-2025-67725?: CVE-2025-67725 is a high-severity vulnerability in Tornadoweb Tornado, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-12-12.
How severe is CVE-2025-67725?: High severity. CVSS v3 base score is 7.5 out of 10.