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Medium 6.1Published Dec 12, 2025

CVE-2025-67724Tornado is a Python web framework and asynchronous networking library.

Updated under an hour ago ()

Does this affect you?

It affects tornadoweb tornado. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom "reason" phrases (the "Not Found" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes). This issue is fixed in version 6.5.3.

CVSS
6.1 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79, CWE-644
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Oct 7, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
tornadoweb tornado
tornadoweb:tornado
before 6.5.3
NVD

References

  • patch
  • release-notes
  • mitigation, vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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