{"id":"CVE-2026-126347","summary":"Tornado: Open redirect via triple-slash redirect paths","details":"Tornado is a Python web framework and asynchronous networking library. In versions through 6.6.0, applications using  tornado.web.RedirectHandler  with URL templates that allow attacker-controlled substitutions to influence the destination can be vulnerable to an open redirect using three or more leading slashes. Differences between Python’s URL parsing and browser URL interpretation allow a crafted destination to redirect a user to an attacker-controlled host. The remediation for CVE-2026-116578 in version 6.6.0 did not fully address this case. This issue is fixed in version 6.6.1.","aliases":["GHSA-5cjw-f85j-cv6r"],"modified":"2026-11-14T02:47:28.309647225Z","published":"2026-11-12T21:52:22.374Z","database_specific":{"unresolved_ranges":[{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"fixed":"6.6.1"}],"source":"AFFECTED_FIELD"}]},{"extracted_events":[{"range":[{"fixed":"6.6.1"}],"source":"DESCRIPTION"}]}],"cna_assigner":"GitHub_M","cwe_ids":["CWE-601"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126347.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126347.json"},{"type":"ADVISORY","url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-5cjw-f85j-cv6r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126347"},{"type":"FIX","url":"https://github.com/tornadoweb/tornado/commit/c503241622c0efe7c40110d89834ce8b7fead1e4"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/tornadoweb/tornado","events":[{"introduced":"0"},{"fixed":"c503241622c0efe7c40110d89834ce8b7fead1e4"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"0"},{"last_affected":"6.6.0"}],"source":"DESCRIPTION"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"c503241622c0efe7c40110d89834ce8b7fead1e4"}]}]}}],"versions":["v6.6.0","v6.6.0rc1","v6.6.0b1","v6.6.0a1","v6.5.0","v6.5.0b1","v6.4.1","v6.4.0","v6.4.0b1","v6.3.1","v6.3.0","v6.3.0b1","v6.2.0","v6.2.0b2","v6.2.0b1","v6.1.0","v6.1.0b2","v6.1.0b1","v6.0.0","v6.0.0b1","v5.1.0","v5.0.0","v4.5.0","v4.5.1","v4.4.1","v4.4.0","v4.4.0b1","v4.3.0","v4.3.0b2","v4.3.0b1","v4.2.0","v4.2.0b1","v4.1.0","v4.1.0b2","v4.1.0b1","v4.0.0","v4.0.0b3","v4.0.0b2","v4.0.0b1","v3.2.0","v3.2.0b2","v3.2.0b1","v3.1.0","v3.0.1","v3.0.0","v2.1.1","v2.3.0","v2.2.0","v2.1.0","v2.0.0","v1.2.0","v1.1.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126347.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N"}]}