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

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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

137 pypi packages depend on lxml-html-clean (21 direct, 117 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.