GHSA-4542-p56h-8xww — typo3/neos
GHSA-4542-p56h-8xww is a security vulnerability in typo3/neos. A fix is available for typo3/neos — see the affected versions and patch details below.
Cross-Site Scripting (XSS) vulnerabilities in Neos
Real-World Exposure
typo3/neos🐘typo3/neosReal-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
It has been discovered that Neos is vulnerable to several XSS attacks. Through these vulnerabilities, an attacker could tamper with page rendering, redirect victims to a fake login page, or capture user credentials (such as cookies). With the potential backdoor upload an attacker could gain access to the server itself, to an extent mainly limited by the server setup.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/neos | ≥ 1.2.0&&< 1.2.13 | 1.2.13composer require typo3/neos:^1.2.13 |
| 🐘Packagist | typo3/neos | ≥ 2.0.0&&< 2.0.4 | 2.0.4composer require typo3/neos:^2.0.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/neos, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/neos to 1.2.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4542-p56h-8xww 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-4542-p56h-8xww can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4542-p56h-8xww. 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-4542-p56h-8xww in your dependencies?
O3 Security finds GHSA-4542-p56h-8xww across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.