CVE-2026-28348: Fedoralovespython Lxml Html Clean

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the _has_sneaky_javascript() method strips backslashes before checking for dangerous CSS keywords. This causes CSS Unicode escape sequences to bypass the @import and expression() filters, allowing external CSS loading or XSS in older browsers. This issue has been patched in version 0.4.4.

Affected products

• Fedoralovespython Lxml Html Clean: before 0.4.4 (fixed in 0.4.4)

Published 2026-03-05. Last modified 2026-06-17.