CVE-2023-47125 is a medium-severity (CVSS 4.7) Cross-site Scripting (XSS) vulnerability in typo3/html-sanitizer. A fix is available for typo3/html-sanitizer — see the affected versions and patch details below.
By-passing Cross-Site Scripting Protection in HTML Sanitizer
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-47125.
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
typo3/html-sanitizer🐘typo3/html-sanitizerReal-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
CVSS:
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C(4.4)
Problem
DOM processing instructions are not handled correctly. This allows bypassing the cross-site scripting mechanism of typo3/html-sanitizer.
Solution
Update to typo3/html-sanitizer versions 1.5.3 or 2.1.4 that fix the problem described.
Credits
Thanks to Yaniv Nizry and Niels Dossche who reported this issue, and to TYPO3 core & security team member Oliver Hader who fixed the issue.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/html-sanitizer | ≥ 1.0.0&&< 1.5.3 | 1.5.3composer require typo3/html-sanitizer:^1.5.3 |
| 🐘Packagist | typo3/html-sanitizer | ≥ 2.0.0&&< 2.1.4 | 2.1.4composer require typo3/html-sanitizer:^2.1.4 |
Affected Products
html sanitizertypo3typo3typo3Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/html-sanitizer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/html-sanitizer to 1.5.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-47125 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-2023-47125 in your dependencies?
Find it across Packagist, including transitive dependencies.