{"id":"UBUNTU-CVE-2021-23980","details":"A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.","modified":"2026-03-10T02:33:03.021997Z","published":"2023-02-16T22:15:00Z","related":["USN-8077-1"],"upstream":["CVE-2021-23980"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-23980"},{"type":"REPORT","url":"https://github.com/mozilla/bleach/security/advisories/GHSA-vv2x-vrpj-qqpq"},{"type":"REPORT","url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1689399"},{"type":"REPORT","url":"https://github.com/mozilla/bleach/commit/79b7a3c5e56a09d1d323a5006afa59b56162eb13"},{"type":"REPORT","url":"https://github.com/mozilla/bleach/commit/d398c89e54ced6b1039d3677689707456ba42dec"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-23980"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8077-1"}],"affected":[{"package":{"name":"python-bleach","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-bleach@1.4.2-1ubuntu0.1~esm1?arch=source&distro=esm-apps/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.2-1ubuntu0.1~esm1"}]}],"versions":["1.4-1","1.4.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python-bleach","binary_version":"1.4.2-1ubuntu0.1~esm1"},{"binary_name":"python3-bleach","binary_version":"1.4.2-1ubuntu0.1~esm1"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-23980.json"}},{"package":{"name":"python-bleach","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/python-bleach@2.1.2-1ubuntu0.1~esm1?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.2-1ubuntu0.1~esm1"}]}],"versions":["2.0-1","2.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python-bleach","binary_version":"2.1.2-1ubuntu0.1~esm1"},{"binary_name":"python3-bleach","binary_version":"2.1.2-1ubuntu0.1~esm1"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-23980.json"}},{"package":{"name":"python-bleach","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/python-bleach@3.1.1-1ubuntu0.1~esm1?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.1-1ubuntu0.1~esm1"}]}],"versions":["3.1.0-1","3.1.0-2","3.1.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-bleach","binary_version":"3.1.1-1ubuntu0.1~esm1"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-23980.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}