{"id":"UBUNTU-CVE-2026-116578","details":"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.","modified":"2026-10-28T20:15:58.315516159Z","published":"2026-10-26T21:18:00Z","upstream":["CVE-2026-116578"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-116578"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-116578"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-pw9p-v7r6-gx4p"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/pull/3786"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/commit/940ea725bdd9bc68231d68a105eef17ea6e11233"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/commit/cc75ab0eb3af459c714895a49f682ad354f50117"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/commit/ccb6a2e5482f17997efd4a74b8200d5b4babc035"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/releases/tag/v6.6.0"}],"affected":[{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.1-1ubuntu2","4.2.1-1ubuntu3","4.2.1-1ubuntu3.1","4.2.1-1ubuntu3.1+esm1","4.2.1-1ubuntu3.1+esm2","4.2.1-1ubuntu3.1+esm3","4.2.1-1ubuntu3.1+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"python-tornado","binary_version":"4.2.1-1ubuntu3.1+esm4"},{"binary_name":"python3-tornado","binary_version":"4.2.1-1ubuntu3.1+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.5.1-2.1~build2","4.5.2-1","4.5.3-1","4.5.3-1ubuntu0.1","4.5.3-1ubuntu0.2","4.5.3-1ubuntu0.2+esm1","4.5.3-1ubuntu0.2+esm2","4.5.3-1ubuntu0.2+esm3","4.5.3-1ubuntu0.2+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"python-tornado","binary_version":"4.5.3-1ubuntu0.2+esm4"},{"binary_version":"4.5.3-1ubuntu0.2+esm4","binary_name":"python3-tornado"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.1.1-4ubuntu1","5.1.1-4ubuntu5","6.0.3+really5.1.1-2","6.0.3+really5.1.1-2build1","6.0.3+really5.1.1-2build2","6.0.3+really5.1.1-3","6.0.3+really5.1.1-3ubuntu0.1~esm1","6.0.3+really5.1.1-3ubuntu0.1~esm3","6.0.3+really5.1.1-3ubuntu0.1~esm5","6.0.3+really5.1.1-3ubuntu0.1~esm7"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.0.3+really5.1.1-3ubuntu0.1~esm7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.1.0-1build1","6.1.0-2","6.1.0-3","6.1.0-3build1","6.1.0-3ubuntu0.1~esm1","6.1.0-3ubuntu0.1~esm2","6.1.0-3ubuntu0.1~esm4","6.1.0-3ubuntu0.1~esm5","6.1.0-3ubuntu0.1~esm6"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.1.0-3ubuntu0.1~esm6"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.3.2-1","6.4.0-0ubuntu1","6.4.0-1","6.4.0-1build1","6.4.0-1ubuntu0.1","6.4.0-1ubuntu0.2","6.4.0-1ubuntu0.4","6.4.0-1ubuntu0.5","6.4.0-1ubuntu0.6"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.4.0-1ubuntu0.6"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.5.4-0.1","6.5.5-2","6.5.5-4","6.5.5-5","6.5.5-5ubuntu1.1"],"ecosystem_specific":{"binaries":[{"binary_version":"6.5.5-5ubuntu1.1","binary_name":"python3-tornado"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116578.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"i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