Arbitrary HTML present after sanitization because of unicode normalization

ImpactIf using keeptypographicwhitespace=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. PatchesThe problem has been fixed in 2.4.2. WorkaroundsSet...

PT-2024-25688

Name of the Vulnerable Software and Affected Versions html-sanitizer versions prior to 2.4.2 Description The issue concerns 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...