HTTP Header Injection Affecting tornado package, versions [,6.5.3)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-TORNADO-14400978
- published12 Dec 2025
- disclosed12 Dec 2025
- creditFinder16
Introduced: 12 Dec 2025
CVE-2025-67724 (opens in a new tab)How to fix?
Upgrade tornado to version 6.5.3 or higher.
Overview
tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.
Affected versions of this package are vulnerable to HTTP Header Injection via the reason argument in HTTP status handling. An attacker can inject arbitrary HTTP headers or execute malicious scripts in the browser by supplying crafted input to the RequestHandler.set_status or tornado.web.HTTPError parameters.
##Workaround
This issue can be mitigated by controlling the usage of untrusted data for the reason argument.