CVE-2024-28235 is a high-severity (CVSS 8.3) Information Exposure vulnerability in contao/core-bundle. A fix is available for contao/core-bundle — see the affected versions and patch details below.
Contao possible cookie sharing with external domains while checking protected pages for broken links
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-28235.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
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
Contao is an open source content management system. Starting in version 4.9.0 and prior to versions 4.13.40 and 5.3.4, when checking for broken links on protected pages, Contao sends the cookie header to external urls as well, the passed options for the http client are used for all requests. Contao versions 4.13.40 and 5.3.4 have a patch for this issue. As a workaround, disable crawling protected pages.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | contao/core-bundle | ≥ 4.9.0&&< 4.13.40 | 4.13.40composer require contao/core-bundle:^4.13.40 |
| 🐘Packagist | contao/core-bundle | ≥ 5.0.0-RC1&&< 5.3.4 | 5.3.4composer require contao/core-bundle:^5.3.4 |
Affected Products
contaocontaoDetection & 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 4.13.40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-28235 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2024-28235 in your dependencies?
Find it across Packagist, including transitive dependencies.