CVE-2024-52595

HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through

MEDIUM
6.1
CVSS Score
Published: November 19, 2024 at 09:27 PM UTC
Updated: June 17, 2026 at 08:07 AM UTC
2 products affected across 2 vendorsLxml Html CleanLxml Html Clean

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.0, the HTML Parser in lxml does not properly handle context-switching for special HTML tags such as `<svg>`, `<math>` and `<noscript>`. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content. Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue. As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability. Via `remove_tags`, one may specify tags to remove - their content is moved to their parents' tags. Via `kill_tags`, one may specify tags to be removed completely. Via `allow_tags`, one may restrict the set of permissible tags, excluding context-switching tags like `<svg>`, `<math>` and `<noscript>`.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.4.0
Affected range stops below 0.4.0, so it looks safe — our inference, not a vendor statement
v < 0.4.0
Affected range stops below 0.4.0, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79CWE-83CWE-184

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