CVE-2026-28348

MEDIUM

lxml_html_clean < 0.4.4 - Cross-Site Scripting via CSS Unicode Escape Sequence Bypass

Title source: llm
STIX 2.1

Description

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.

References (2)

Core 2

Scores

CVSS v3 6.1
EPSS 0.0023
EPSS Percentile 13.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-116
Status published
Products (1)
fedoralovespython/lxml_html_clean < 0.4.4
Published Mar 05, 2026
Tracked Since Mar 06, 2026