CVE-2026-28348
lxml_html_clean: CSS @import Filter Bypass via Unicode Escapes
- State
- Published
- Severity
- 6.1 Medium
- Published
- Mar 5, 2026
- Updated
- Mar 6, 2026
- Reserved
- Feb 26, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.1 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-116 Improper Encoding or Escaping of Output
Affected Products
| Product | Versions |
|---|---|
lxml_html_cleanfedora-python |
|
References
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