CVE-2024-52595 | HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through

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>`.

Published: 2024-11-19 Last update: 2024-11-25 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2024-52595 is rated Moderate Risk (54/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.50%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-52595

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-10 0.37% 0.50% +0.13%
2 2026-02-13 0.24% 0.37% +0.13%
3 2025-12-28 0.24%

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-52595

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.7 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 5.5 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]

Weakness enumeration for CVE-2024-52595

GitHub Security Advisory for CVE-2024-52595

GHSA-5jfw-gq64-q45f · Severity: high · Ecosystem: pip — HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through

OS Trackers for CVE-2024-52595

vendor priority summary link
debian not yet assigned CVE-2024-52595 not yet assigned priority: Debian including 1 source packages (lxml-html-clean), 3 status rows across 3 suites (forky, sid, trixie): resolved 3. https://security-tracker.debian.org/tracker/CVE-2024-52595
ubuntu medium CVE-2024-52595 medium priority: Ubuntu including 1 source packages (lxml-html-clean), 7 status rows across 7 suites (focal, jammy, noble, oracular, plucky, questing, upstream): needs-triage 3, DNE 2, ignored 2. https://ubuntu.com/security/CVE-2024-52595

Affected software / configurations for CVE-2024-52595

Vendor Product Version Raw CPE
fedoralovespython lxml_html_clean < 0.4.0 cpe:2.3:a:fedoralovespython:lxml_html_clean:*:*:*:*:*:python:*:*

References for CVE-2024-52595

cvelogic Threat Intelligence