GHSA-6qjf-7g3j-qx25
MEDIUMNeos CMS Cross Site Scripting vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
neos/media-browser🐘neos/media-browser🐘neos/media-browser🐘neos/media-browser🐘neos/media-browserReal-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
Cross Site Scripting (XSS) vulnerability in Neos CMS 8.3.3 allows a remote authenticated attacker to execute arbitrary code via a crafted SVG file uploaded to the neos/management/media component. To make use of this attack vector, the attacker must either be able to upload a maliciously crafted file or coerce someone with the needed access to upload said file to Neos. Even if such a file is uploaded and subsequently delivered, it is possible to use CSP to protect against attacks being executed from such a file.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | neos/media-browser | all versions | 7.3.19 |
| 🐘Packagist | neos/media-browser | ≥ 8.0.0&&< 8.0.16 | 8.0.16 |
| 🐘Packagist | neos/media-browser | ≥ 8.1.0&&< 8.1.11 | 8.1.11 |
| 🐘Packagist | neos/media-browser | ≥ 8.2.0&&< 8.2.11 | 8.2.11 |
| 🐘Packagist | neos/media-browser | ≥ 8.3.0&&< 8.3.9 | 8.3.9 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for neos/media-browser. 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 neos/media-browser to 7.3.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6qjf-7g3j-qx25 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-6qjf-7g3j-qx25 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-6qjf-7g3j-qx25. 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-6qjf-7g3j-qx25 in your dependencies?
O3 detects GHSA-6qjf-7g3j-qx25 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.