{"id":"CVE-2026-116578","state":"PUBLISHED","title":"Tornado: Open redirect in RedirectHandler via protocol-relative URLs","description":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.6, tornado.web.RedirectHandler URL templates can place regex-capture substitutions where crafted request paths change the redirect scheme or network location. Affected placements include substitutions at the start of a path, directly after a fixed host, or at the beginning of the template, including protocol-relative, absolute, backslash, encoded, host-extension, and user-info variants interpreted by browsers as attacker-controlled destinations. Static templates and substitutions after a fixed host followed by a slash are not affected. An attacker can use the resulting open redirect on the application's domain for phishing. This issue is fixed in version 6.6.","publishedAt":"2026-10-26T20:22:32.217Z","updatedAt":"2026-10-30T14:28:27.285Z","severity":{"score":2.1,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["tornadoweb tornado"],"affected":[{"vendor":"tornadoweb","product":"tornado","versions":[{"version":"< 6.6","status":"affected"}]}],"references":["https://github.com/tornadoweb/tornado/security/advisories/GHSA-pw9p-v7r6-gx4p","https://github.com/tornadoweb/tornado/pull/3786","https://github.com/tornadoweb/tornado/commit/940ea725bdd9bc68231d68a105eef17ea6e11233","https://github.com/tornadoweb/tornado/commit/cc75ab0eb3af459c714895a49f682ad354f50117","https://github.com/tornadoweb/tornado/commit/ccb6a2e5482f17997efd4a74b8200d5b4babc035","https://github.com/tornadoweb/tornado/releases/tag/v6.6.0"],"weaknesses":["CWE-601"],"ingestedAt":"2026-10-30T14:38:06.611Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/116xxx/CVE-2026-116578.json","commit":"d88c0a1c0d885dc592725fb56de7f3fed94f6783","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-116578","state":"PUBLISHED","datePublished":"2026-10-26T20:22:32.217Z","dateUpdated":"2026-10-30T14:28:27.285Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-26T15:03:39.035Z"},"containers":{"cna":{"title":"Tornado: Open redirect in RedirectHandler via protocol-relative URLs","descriptions":[{"lang":"en","value":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.6, tornado.web.RedirectHandler URL templates can place regex-capture substitutions where crafted request paths change the redirect scheme or network location. Affected placements include substitutions at the start of a path, directly after a fixed host, or at the beginning of the template, including protocol-relative, absolute, backslash, encoded, host-extension, and user-info variants interpreted by browsers as attacker-controlled destinations. Static templates and substitutions after a fixed host followed by a slash are not affected. An attacker can use the resulting open redirect on the application's domain for phishing. This issue is fixed in version 6.6."}],"affected":[{"vendor":"tornadoweb","product":"tornado","versions":[{"version":"< 6.6","status":"affected"}]}],"references":[{"url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-pw9p-v7r6-gx4p","name":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-pw9p-v7r6-gx4p","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/tornadoweb/tornado/pull/3786","name":"https://github.com/tornadoweb/tornado/pull/3786","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/commit/940ea725bdd9bc68231d68a105eef17ea6e11233","name":"https://github.com/tornadoweb/tornado/commit/940ea725bdd9bc68231d68a105eef17ea6e11233","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/commit/cc75ab0eb3af459c714895a49f682ad354f50117","name":"https://github.com/tornadoweb/tornado/commit/cc75ab0eb3af459c714895a49f682ad354f50117","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/commit/ccb6a2e5482f17997efd4a74b8200d5b4babc035","name":"https://github.com/tornadoweb/tornado/commit/ccb6a2e5482f17997efd4a74b8200d5b4babc035","tags":["x_refsource_MISC"]},{"url":"https://github.com/tornadoweb/tornado/releases/tag/v6.6.0","name":"https://github.com/tornadoweb/tornado/releases/tag/v6.6.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":2.1,"baseSeverity":"LOW","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-601","lang":"en","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-26T20:22:32.217Z"},"source":{"advisory":"GHSA-pw9p-v7r6-gx4p","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T14:28:17.724428Z","id":"CVE-2026-116578","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T14:28:27.285Z"}}]}}}