CVE-2024-52595
HIGHCVE-2024-52595 is a high-severity (CVSS 7.7) Cross-site Scripting (XSS) vulnerability in lxml-html-clean. O3 Security confirms whether CVE-2024-52595 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through
Blast Radius
lxml-html-cleanReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | lxml-html-clean | all versions | 0.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lxml-html-clean. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update lxml-html-clean to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-52595 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2024-52595 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2024-52595. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-52595 in your dependencies?
O3 detects CVE-2024-52595 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.