CVE-2026-28348 Details
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.
A vulnerability in lxml_html_clean versions prior to 0.4.4 allows CSS Unicode escape sequences to bypass filters intended to block dangerous @import and expression() keywords. This flaw could lead to the loading of external CSS or cross-site scripting (XSS) attacks in older browsers. The issue arises because the vulnerability's method for detecting harmful CSS keywords improperly handles Unicode escape sequences, allowing them to evade security checks. As a result, malicious styles can be injected and executed, particularly in Internet Explorer, where expression() can be used for XSS attacks.
Users can upgrade to lxml_html_clean version 0.4.4 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Mar 6, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-hw26-mmpg-fqfg | CISA-ADP | ExploitVendor Advisory |
| https://github.com/fedora-python/lxml_html_clean/commit/2ef732667ddbc74ea59847bcf24b75809aaeed3b | [email protected] | Patch |
| https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-hw26-mmpg-fqfg | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-116 | Improper Encoding or Escaping of Output | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| fedoralovespython lxml html clean | < 0.4.4 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Mar 9, 2026 | Initial Analysis | [email protected] |
| Mar 6, 2026 | CVE Modified | CISA-ADP |
| Mar 5, 2026 | New CVE Received | [email protected] |