CVE-2022-36020
MEDIUMCVE-2022-36020 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in typo3/html-sanitizer. O3 Security confirms whether CVE-2022-36020 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Bypass of Cross-Site Scripting Protection in typo3/html-sanitizer
Blast Radius
typo3/html-sanitizer🐘typo3/html-sanitizer🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms🐘typo3/cmsReal-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
The typo3/html-sanitizer package is an HTML sanitizer, written in PHP, aiming to provide XSS-safe markup based on explicitly allowed tags, attributes and values. Due to a parsing issue in the upstream package masterminds/html5, malicious markup used in a sequence with special HTML comments cannot be filtered and sanitized. This allows for a bypass of the cross-site scripting mechanism of typo3/html-sanitizer. This issue has been addressed in versions 1.0.7 and 2.0.16 of the typo3/html-sanitizer package. Users are advised to upgrade. There are no known workarounds for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/html-sanitizer | ≥ 1.0.0&&< 1.0.7 | 1.0.7 |
| 🐘Packagist | typo3/html-sanitizer | ≥ 2.0.0&&< 2.0.16 | 2.0.16 |
| 🐘Packagist | typo3/cms-core | ≥ 10.0.0&&< 10.4.32 | 10.4.32 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.5.16 | 11.5.16 |
| 🐘Packagist | typo3/cms | ≥ 10.0.0&&< 10.4.32 | 10.4.32 |
| 🐘Packagist | typo3/cms | ≥ 11.0.0&&< 11.5.16 | 11.5.16 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/html-sanitizer. 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 typo3/html-sanitizer to 1.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-36020 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-2022-36020 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-2022-36020. 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-2022-36020 in your dependencies?
O3 detects CVE-2022-36020 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.