CVE-2024-34356 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.
TYPO3 vulnerable to Cross-Site Scripting in the Form Manager Module
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-2024-34356.
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/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms-coreReal-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
Problem
The form manager backend module is vulnerable to cross-site scripting. Exploiting this vulnerability requires a valid backend user account with access to the form module.
Solution
Update to TYPO3 versions 9.5.48 ELTS, 10.4.45 ELTS, 11.5.37 LTS, 12.4.15 LTS, 13.1.1 that fix the problem described.
Credits
Thanks to TYPO3 core & security team member Benjamin Franzke who reported and fixed the issue.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 9.0.0&&< 9.5.48 | 9.5.48composer require typo3/cms-core:^9.5.48 |
| 🐘Packagist | typo3/cms-core | ≥ 10.0.0&&< 10.4.45 | 10.4.45composer require typo3/cms-core:^10.4.45 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.5.37 | 11.5.37composer require typo3/cms-core:^11.5.37 |
| 🐘Packagist | typo3/cms-core | ≥ 12.0.0&&< 12.4.15 | 12.4.15composer require typo3/cms-core:^12.4.15 |
| 🐘Packagist | typo3/cms-core | ≥ 13.0.0&&< 13.1.1 | 13.1.1composer require typo3/cms-core:^13.1.1 |
Affected Products
typo3typo3Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-core to 9.5.48 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-34356 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-2024-34356 in your dependencies?
Find it across Packagist, including transitive dependencies.