CVE-2007-3498 is a medium-severity (CVSS 6.1) vulnerability in ezyang/htmlpurifier. A fix is available for ezyang/htmlpurifier — see the affected versions and patch details below.
HTML Purifier Cross-site Scripting vulnerability
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
ezyang/htmlpurifierReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Cross-site scripting (XSS) vulnerability in smoketests/configForm.php in HTML Purifier before 2.0.1 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors related to "unescaped print_r output."
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | ezyang/htmlpurifier | all versions | 2.0.1composer require ezyang/htmlpurifier:^2.0.1 |
Affected Products
htmlpurifierhtmlpurifierDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ezyang/htmlpurifier, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ezyang/htmlpurifier to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2007-3498 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2007-3498 in your dependencies?
Find it across Packagist, including transitive dependencies.