GHSA-wg8h-gxf4-g4gh is a medium-severity (CVSS 6.1) vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.
TYPO3 Cross-Site Scripting in Online Media Asset Rendering
Real-World Exposure
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
Failing to properly encode user input, online media asset rendering (*.youtube and *.vimeo files) is vulnerable to cross-site scripting. A valid backend user account or write access on the server system (e.g. SFTP) is needed in order to exploit this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 8.0.0&&< 8.7.21 | 8.7.21composer require typo3/cms-core:^8.7.21 |
| 🐘Packagist | typo3/cms-core | ≥ 9.0.0&&< 9.5.2 | 9.5.2composer require typo3/cms-core:^9.5.2 |
Detection & 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 8.7.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wg8h-gxf4-g4gh 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-wg8h-gxf4-g4gh can be triaged on real exposure rather than presence alone.
Tailored to GHSA-wg8h-gxf4-g4gh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-wg8h-gxf4-g4gh in your dependencies?
O3 Security finds GHSA-wg8h-gxf4-g4gh across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.