{"id":"CVE-2026-126347","aliases":["GHSA-5cjw-f85j-cv6r"],"url":"https://o3.security/vulnerability/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.","published":"2026-11-12T21:52:22.374Z","modified":"2026-11-15T02:46:07.758049222Z","cvss":{"score":3.1,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"tornado","fixedVersion":"6.6.1"}],"fix":{"url":"https://github.com/tornadoweb/tornado/commit/c503241622c0efe7c40110d89834ce8b7fead1e4","label":"tornadoweb/tornado@c503241"},"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"},{"type":"PACKAGE","url":"https://github.com/tornadoweb/tornado"},{"type":"WEB","url":"https://github.com/tornadoweb/tornado/releases/tag/v6.6.1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-11-15T02:46:07.758049222Z"}}