CVE-2026-28348
MEDIUM6.1EPSS 0.05%lxml-html-clean has CSS @import Filter Bypass via Unicode Escapes
Published: 3/2/2026Modified: 4/28/2026
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.
Affected packages (2)
- Debian/lxml-html-cleanfrom 0
- PyPI/lxml-html-cleanfrom 0, < 0.4.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References (5)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-28348
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-28348
- PATCHhttps://github.com/fedora-python/lxml_html_clean
- WEBhttps://github.com/fedora-python/lxml_html_clean/commit/2ef732667ddbc74ea59847bcf24b75809aaeed3b
- WEBhttps://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-hw26-mmpg-fqfg