CVE-2025-67724
Tornado vulnerable to Header Injection and XSS via reason argument
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.24% · top 85% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.4.
Weakness
Affected products
- affected < 6.5.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPItornadoGHSA-pr2v-jx2c-wg9f (opens in a new tab)
References (3)
- https://github.com/tornadoweb/tornado/security/advisories/GHSA-pr2v-jx2c-wg9f (opens in a new tab)x_refsource_CONFIRM
- https://github.com/tornadoweb/tornado/commit/9c163aebeaad9e6e7d28bac1f33580eb00b0e421 (opens in a new tab)x_refsource_MISC
- https://github.com/tornadoweb/tornado/releases/tag/v6.5.3 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-pr2v-jx2c-wg9f (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-67724)Record last updated .