CVE-2026-28350CWE-116

lxml_html_clean: <base> tag injection through default Cleaner configuration

Medium · published March 5, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
20.3
In the wild
Unconfirmed
What it is

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the <base> tag passes through the default Cleaner configuration. While page_structure=True removes html, head, and title tags, there is no specific handling for <base>, allowing an attacker to inject it and hijack relative links on the page. This issue has been patched in version 0.4.4.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00288 · 20.3th percentile
Weakness
CWE-116 · Improper Encoding or Escaping of Output
Published
2026-03-05T19:49Z
EPSS history
Timeline
  • 05 MAR 19:49Z
    lxml_html_clean: <base> tag injection through default Cleaner configuration
    cvelistv5