PYSEC-2026-2614 `lxml_html_clean.Cleaner` does not strip `javascript:` URLs from namespaced URL attributes

lxmlhtmlclean.Cleaner does not strip javascript: URLs from namespaced URL attributes xlink:href Reporter: Guillem Lefait · Date: 2026-05-10 Affected: lxml ≤ 6.1.0 and lxmlhtmlclean ≤ 0.4.4 latest stable Confirmed against: lxml 6.1.0 + lxmlhtmlclean 0.4.4 on Python 3.13.5, 3.14.4, and 3.15.0a8...

Incomplete List of Disallowed Inputs

Overview lxml-html-clean is a HTML cleaner from lxml project Affected versions of this package are vulnerable to Incomplete List of Disallowed Inputs in the Cleaner process when handling namespaced URL attributes such as xlink:href with the safeattrsonly=False configuration. An attacker can execu...