GHSA-8366-xmgf-334f
MEDIUMREDAXO allows Authenticated Reflected Cross Site Scripting - packages installation
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
redaxo/sourceReal-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
Summary
Reflected cross-site scripting (XSS) is a type of web vulnerability that occurs when a web application fails to properly sanitize user input, allowing an attacker to inject malicious code into the application's response to a user's request. When the user's browser receives the response, the malicious code is executed, potentially allowing the attacker to steal sensitive information or take control of the user's account.
Details
On the latest version of Redaxo, v5.18.2, the rex-api-result parameter is vulnerable to Reflected cross-site scripting (XSS) on the page of AddOns.
PoC
- Login Redaxo as administrative user.
- Navigate to the URL: http://localhost/redaxo/index.php?page=packages&rex-api-call=package&&rex-api-result={%22succeeded%22%3Atrue%2C%22message%22%3A%22%3Cimg%20src=x%20onerror=alert(document.domain);%3E%22}, the XSS executes.
Impact
This can lead to various security risks, including session hijacking, phishing attacks and malware distribution. History page visible to administrative user and when an administrator views the infected page, the attacker may gain elevated privileges, further compromising the system.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | redaxo/source | ≥ 5.0.0&&< 5.18.3 | 5.18.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for redaxo/source. 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 redaxo/source to 5.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8366-xmgf-334f 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-8366-xmgf-334f 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-8366-xmgf-334f. 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-8366-xmgf-334f in your dependencies?
O3 detects GHSA-8366-xmgf-334f across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.