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Fencer Intel
high 7.7

CVE-2024-52595 json

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

published last yr. modified 4mo ago also EUVD-2024-0206 , GHSA-5jfw-gq64-q45f , PYSEC-2024-160

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

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>`.

Patch / fix

  • pypi lxml-html-clean 0.4.0
  • fedoralovespython lxml_html_clean 0.4.0
  • lxml-html-clean Debian 14, Debian 13 0.4.1-1

debian advisories DEBIAN-CVE-2024-52595

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-52595 updated cvss 7.7

python-lxml-html-clean: HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H
GitHub 3.1 7.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
OSV 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
pypi lxml-html-clean
<0.4.0
0.4.0

Affected products

  • fedora-python lxml_html_clean

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-83 Improper Neutralization of Script in Attributes in a Web Page
  • CWE-184 Incomplete List of Disallowed Inputs

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of fedora-python/lxml_html_clean published their own advisory on GitHub. Reviewed sources take precedence over it.