GHSA-8mq9-fqv8-59wf
MEDIUMGHSA-8mq9-fqv8-59wf is a medium-severity (CVSS 6.4) Cross-site Scripting (XSS) vulnerability in typo3/cms-core. O3 Security confirms whether GHSA-8mq9-fqv8-59wf is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-Site Scripting in Page Preview
Real-World Exposure
typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms🐘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
Meta
- CVSS:
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC(5.0)
Problem
Failing to properly encode Page TSconfig settings, corresponding page preview module (Web>View) is vulnerable to persistent cross-site scripting. A valid backend user account is needed to exploit this vulnerability.
Solution
Update to TYPO3 versions 9.5.28, 10.4.18, 11.3.1 that fix the problem described.
Credits
Thanks to TYPO3 core merger Oliver Bartsch who reported and fixed the issue.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 9.0.0&&< 9.5.28 | 9.5.28 |
| 🐘Packagist | typo3/cms-core | ≥ 10.0.0&&< 10.4.18 | 10.4.18 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.3.1 | 11.3.1 |
| 🐘Packagist | typo3/cms | ≥ 10.0.0&&< 10.4.18 | 10.4.18 |
| 🐘Packagist | typo3/cms | ≥ 11.0.0&&< 11.3.1 | 11.3.1 |
| 🐘Packagist | typo3/cms | ≥ 9.0.0&&< 9.5.28 | 9.5.28 |
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. 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/cms-core to 9.5.28 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8mq9-fqv8-59wf 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 GHSA-8mq9-fqv8-59wf 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 GHSA-8mq9-fqv8-59wf. 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-8mq9-fqv8-59wf in your dependencies?
O3 detects GHSA-8mq9-fqv8-59wf across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.