{"id":"CVE-2025-67724","title":"Tornado is a Python web framework and asynchronous networking library","summary":"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 erro…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","cwe":["CWE-79","CWE-644"],"vendor":"tornadoweb","product":"tornado","affected":["tornado < 6.5.3"],"patched":["tornado 6.5.3"],"published":"2025-12-12","updated":"2026-10-07","sourceUpdated":"2026-10-07T20:10:01.970","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-67724","references":[{"url":"https://github.com/tornadoweb/tornado/commit/9c163aebeaad9e6e7d28bac1f33580eb00b0e421","label":"security-advisories@github.com"},{"url":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.3","label":"security-advisories@github.com"},{"url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-pr2v-jx2c-wg9f","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-67724.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-67724"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2421719"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-67724"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-67724"}],"tags":["nvd","csaf","vex","red-hat","osv","pip"],"epss":0.0024,"epssPercentile":0.15028,"aliases":["PYSEC-2025-265","GHSA-pr2v-jx2c-wg9f"],"ecosystem":"pip","scores":{"nvd":5.4,"vendor":5.4,"osv":6.1},"ingestedAt":"2026-07-13T18:58:06.906Z","slug":"CVE-2025-67724","body":"## Overview\n\nTornado 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.\n\n## Affected\n\n- `tornado < 6.5.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `tornado 6.5.3`\n\n## Package advisory (CVE-2025-67724)\n\nAffected packages:\n\n- `tornado < 6.5.3`\n\nPatched in:\n\n- `tornado 6.5.3`\n\nSource: https://osv.dev/vulnerability/PYSEC-2025-265\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: External Secrets Operator for Red Hat OpenShift, external secrets operator for Red Hat OpenShift - Tech Preview, OpenShift Service Mesh 2, OpenShift Service Mesh 3, Red Hat Advanced Cluster Security 4, Red Hat Enterprise Linux 10, … · no fix planned: External Secrets Operator for Red Hat OpenShift, external secrets operator for Red Hat OpenShift - Tech Preview, OpenShift Service Mesh 2, OpenShift Service Mesh 3, … · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-67724.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":209499,"id":"CVE-2025-67724","ts":1790149052228,"field":"cvss","old":"6.1","new":"5.4"}]}