CVE-2025-67724Medium· 5.4▾ SunlitTornado 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…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 29.7 · likelihood 0 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 30.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
0.2% → 0.2%
6.1 → 5.4
Last analysed / modified upstream
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.
tornado < 6.5.3Upgrade past the affected range:
tornado 6.5.3Affected packages:
tornado < 6.5.3Patched in:
tornado 6.5.3Source: https://osv.dev/vulnerability/PYSEC-2025-265
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2025-67726High· 7.5Tornado is a Python web framework and asynchronous networking library
CVE-2025-67725High· 7.5Tornado is a Python web framework and asynchronous networking library
CVE-2026-103262High· 7.5Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response
CVE-2026-103263Medium· 5.9Tornado before 6.5.9 contains a path traversal vulnerability in StaticFileHandler that follows symbolic links inside the static root without confirming the resolved target stays within it
CVE-2026-103261Medium· 5.3Tornado before 6.5.9 fails to limit the number of query string fields in HTTPServerRequest.__init__, allowing remote attackers to cause event-loop stalling by sending requests with thousands of query parameters
CVE-2024-58384Medium· 5.4Tornado before 6.4.1 contains a CRLF injection vulnerability in CurlAsyncHTTPClient that fails to reject carriage return and line feed characters in request headers