What is the CVSS score of CVE-2026-28348?

CVE-2026-28348 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Lxml Html Clean are affected by CVE-2026-28348?

Organizations using lxml_html_clean should be aware of moderate risk from CVE-2026-28348 rated CVSS 6.1. Exploitation could compromise the security of affected deployments.. A patch is available.

Is there a public PoC exploit available for CVE-2026-28348?

Yes, a public proof-of-concept exploit is available for CVE-2026-28348. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-28348?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Lxml Html Clean CVE-2026-28348

MEDIUM

Improper Encoding or Escaping of Output (CWE-116)

2026-03-05 security-advisories@github.com

GHSA-hw26-mmpg-fqfg

XSS Lxml Html Clean Suse Fedoralovespython

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

SUSE

MEDIUM

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

PoC Detected

Mar 09, 2026 - 20:55 vuln.today

Public exploit code

Patch released

Mar 09, 2026 - 20:55 nvd

Patch available

CVE Published

Mar 05, 2026 - 20:16 nvd

MEDIUM 6.1

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

130 pypi packages depend on lxml-html-clean (22 direct, 108 indirect)

Ecosystem-wide dependent count for version 0.4.4.

DescriptionGitHub Advisory

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.

AnalysisAI

lxml_html_clean versions before 0.4.4 fail to properly sanitize CSS Unicode escape sequences in the _has_sneaky_javascript() method, allowing attackers to bypass filters and inject malicious @import statements or XSS payloads. Public exploit code exists for this vulnerability, which affects applications using the library for HTML sanitization. A patch is available in version 0.4.4 and should be applied immediately to prevent CSS-based injection attacks.

Technical ContextAI

Classified as CWE-116 (Improper Encoding or Escaping of Output). Affects Lxml Html Clean. 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.

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 0.4.4.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.