{"id":"CVE-2024-34078","aliases":["DEBIAN-CVE-2024-34078","DLA-3856-1","EUVD-2024-1840","GHSA-wvhx-q427-fgh3","PYSEC-2026-1455","UBUNTU-CVE-2024-34078"],"status":"published","title":"html-sanitizer allows arbitrary HTML present after sanitization because of unicode normalization","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00555,"percentile":0.46789,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2024-05-06T14:33:32Z","modified":"2026-10-28T02:31:08Z","fixes":[{"ecosystem":"PyPI","package":"html-sanitizer","fixed_in":["2.4.2"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:11","package":"python-html-sanitizer","fixed_in":["1.9.1-2+deb11u1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.2"}]}]},{"source":"osv","ecosystem":"Debian:11","package":"python-html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.1-2+deb11u1"}]}],"versions":["1.9.1-2"]},{"source":"osv","ecosystem":"Debian:11","package":"python-html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.1-2+deb11u1"}]}],"versions":["1.9.1-2"]},{"source":"osv","ecosystem":"PyPI","package":"html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.2"}]}],"versions":["1.0.0","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.2.0","1.2.1","1.3.0","1.4.0","1.5.0","1.6.0","1.6.1","1.6.2","1.6.3","1.6.4","1.7.0","1.7.1","1.7.2","1.7.3","1.8.0","1.9.0","1.9.1","1.9.2","1.9.3","2.0.0","2.1.0","2.2.0","2.3.0","2.3.1","2.4.0","2.4.1"]},{"source":"osv","ecosystem":"PyPI","package":"html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.2"}]}],"versions":["1.0.0","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.2.0","1.2.1","1.3.0","1.4.0","1.5.0","1.6.0","1.6.1","1.6.2","1.6.3","1.6.4","1.7.0","1.7.1","1.7.2","1.7.3","1.8.0","1.9.0","1.9.1","1.9.2","1.9.3","2.0.0","2.1.0","2.2.0","2.3.0","2.3.1","2.4.0","2.4.1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"python-html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.9.1-2","1.9.3-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"python-html-sanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2-1"]}],"products":[{"vendor":"matthiask","product":"html-sanitizer"},{"vendor":"typo3","product":"html-sanitizer"}],"references":[{"url":"https://github.com/matthiask/html-sanitizer/security/advisories/GHSA-wvhx-q427-fgh3","tags":["x_refsource_CONFIRM","x_transferred","advisory","web","report"]},{"url":"https://github.com/matthiask/html-sanitizer/commit/48db42fc5143d0140c32d929c46b802f96913550","tags":["x_refsource_MISC","x_transferred","fix","web","report"]},{"url":"https://lists.debian.org/debian-lts-announce/2024/08/msg00000.html","tags":["web"]},{"url":"https://github.com/advisories/GHSA-wvhx-q427-fgh3","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/34xxx/CVE-2024-34078.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-34078","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2024-34078","tags":["advisory"]},{"url":"https://github.com/matthiask/html-sanitizer","tags":["package"]},{"url":"https://pypi.org/project/html-sanitizer","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2024-34078","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2024-34078","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2024-34078","title":"html-sanitizer allows arbitrary HTML present after sanitization because of unicode normalization","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.\n","status":"published","published":"2024-05-06T14:48:47.506Z","modified":"2024-08-26T18:03:11.753Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:34:23.516065Z"}],"euvd":[{"id":"EUVD-2024-1840","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.\n","status":"published","published":"2024-05-06T14:48:47Z","modified":"2024-08-26T18:03:11Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T00:56:11.385487Z"}],"ghsa":[{"id":"GHSA-wvhx-q427-fgh3","title":"Arbitrary HTML present after sanitization because of unicode normalization","description":"### Impact\n\nIf using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization.\n\n### Patches\n\nThe problem has been fixed in 2.4.2.\n\n### Workarounds\n\nSet `keep_typographic_whitespace=True` explicitly, or normalize to NFKC yourself earlier.\n","status":"published","published":"2024-05-06T14:33:32Z","modified":"2024-05-06T14:33:33Z","updated_at":"2026-11-02T14:37:48.08826Z"}],"nvd":[{"id":"CVE-2024-34078","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.\n","status":"published","published":"2024-05-06T15:15:24.187Z","modified":"2026-06-17T07:32:51.77Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:09:56.122111Z"}],"osv":[{"id":"CVE-2024-34078","title":"html-sanitizer allows arbitrary HTML present after sanitization because of unicode normalization","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.\n","status":"published","published":"2024-05-06T14:48:47.506Z","modified":"2026-10-28T02:31:08.881603475Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:44:40.391953Z"},{"id":"DEBIAN-CVE-2024-34078","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.","status":"published","published":"2024-05-06T15:15:24.187Z","modified":"2026-08-27T23:05:04.482352495Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:42.530184Z"},{"id":"UBUNTU-CVE-2024-34078","description":"html-sanitizer is an allowlist-based HTML cleaner. If using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization. The problem has been fixed in 2.4.2.","status":"published","published":"2024-05-06T15:15:00Z","modified":"2025-09-08T17:00:23Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T16:54:50.784131Z"},{"id":"DLA-3856-1","title":"python-html-sanitizer - security update","status":"published","published":"2024-08-26T00:00:00Z","modified":"2026-03-09T01:22:51.157007Z","updated_at":"2026-11-02T15:46:12.203458Z"},{"id":"GHSA-wvhx-q427-fgh3","title":"Arbitrary HTML present after sanitization because of unicode normalization","description":"### Impact\n\nIf using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization.\n\n### Patches\n\nThe problem has been fixed in 2.4.2.\n\n### Workarounds\n\nSet `keep_typographic_whitespace=True` explicitly, or normalize to NFKC yourself earlier.\n","status":"published","published":"2024-05-06T14:33:32Z","modified":"2026-09-10T03:50:14.569601746Z","updated_at":"2026-11-02T15:46:59.131095Z"},{"id":"PYSEC-2026-1455","title":"Arbitrary HTML present after sanitization because of unicode normalization","description":"### Impact\n\nIf using `keep_typographic_whitespace=False` (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization.\n\n### Patches\n\nThe problem has been fixed in 2.4.2.\n\n### Workarounds\n\nSet `keep_typographic_whitespace=True` explicitly, or normalize to NFKC yourself earlier.\n","status":"published","published":"2026-07-07T11:45:42.091141Z","modified":"2026-07-07T17:47:44.646585963Z","updated_at":"2026-11-02T15:52:55.06457Z"}]}}