GHSA-4gpr-p634-922x is a medium-severity (CVSS 6.6) Cross-site Scripting (XSS) vulnerability in contao/core-bundle. 1 public exploit reference exists, so weaponization risk is real. A fix is available for contao/core-bundle — see the affected versions and patch details below.
Cross site scripting via input unit widget
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-4gpr-p634-922x.
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.
How urgent is this, really
GHSA-4gpr-p634-922x plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
contao/core-bundle🐘contao/core-bundle🐘contao/core-bundleReal-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
Impact
Authenticated users can inject malicious code in widgets with units, which is then executed both in the element preview (back end) and on the website (front end).
Patches
Update to Contao 4.9.42, 4.13.28 or 5.1.10.
Workarounds
Disable login for all untrusted back end users.
References
https://contao.org/en/security-advisories/cross-site-scripting-in-widgets-with-units
For more information
If you have any questions or comments about this advisory, open an issue in contao/contao.
Credits
Thanks to Christian Pöschl and Fabian Brenner from usd AG for reporting this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | contao/core-bundle | ≥ 4.0.0&&< 4.9.42 | 4.9.42composer require contao/core-bundle:^4.9.42 |
| 🐘Packagist | contao/core-bundle | ≥ 4.10.0&&< 4.13.28 | 4.13.28composer require contao/core-bundle:^4.13.28 |
| 🐘Packagist | contao/core-bundle | ≥ 5.0.0&&< 5.1.10 | 5.1.10composer require contao/core-bundle:^5.1.10 |
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 contao/core-bundle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update contao/core-bundle to 4.9.42 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4gpr-p634-922x 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-4gpr-p634-922x can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4gpr-p634-922x. 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-4gpr-p634-922x in your dependencies?
O3 Security finds GHSA-4gpr-p634-922x across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.