{"id":"UBUNTU-CVE-2026-35536","details":"In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted characters.","modified":"2026-05-20T16:12:58.329462978Z","published":"2026-04-03T04:16:00Z","related":["USN-8198-1","USN-8198-2"],"upstream":["CVE-2026-35536"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-35536"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-35536"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-78cv-mqj4-43f7"},{"type":"REPORT","url":"https://github.com/tornadoweb/tornado/releases/tag/v6.5.5"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8198-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8198-2"}],"affected":[{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.1-1ubuntu3.1+esm3"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"4.2.1-1ubuntu3.1+esm3","binary_name":"python-tornado"},{"binary_version":"4.2.1-1ubuntu3.1+esm3","binary_name":"python3-tornado"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.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"},{"fixed":"4.5.3-1ubuntu0.2+esm3"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"4.5.3-1ubuntu0.2+esm3","binary_name":"python-tornado"},{"binary_version":"4.5.3-1ubuntu0.2+esm3","binary_name":"python3-tornado"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.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"},{"fixed":"6.0.3+really5.1.1-3ubuntu0.1~esm5"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"6.0.3+really5.1.1-3ubuntu0.1~esm5","binary_name":"python3-tornado"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.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"},{"fixed":"6.1.0-3ubuntu0.1~esm5"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"6.1.0-3ubuntu0.1~esm5","binary_name":"python3-tornado"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.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"},{"fixed":"6.4.0-1ubuntu0.5"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"6.4.0-1ubuntu0.5","binary_name":"python3-tornado"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.2-3ubuntu0.3"}]}],"versions":["6.4.2-1","6.4.2-2","6.4.2-2ubuntu1","6.4.2-3","6.4.2-3ubuntu0.2"],"ecosystem_specific":{"binaries":[{"binary_version":"6.4.2-3ubuntu0.3","binary_name":"python3-tornado"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.4-0.1ubuntu0.1"}]}],"versions":["6.4.2-3","6.5.2-3","6.5.4-0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"6.5.4-0.1ubuntu0.1","binary_name":"python3-tornado"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-35536.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}