CVE-2023-38499 is a low-severity (CVSS 3.7) Information Exposure vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.
typo3/cms-core Information Disclosure due to Out-of-scope Site Resolution
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-2023-38499.
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
typo3/cms-core🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms-coreReal-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
CVSS:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C(3.5)
Problem
In multi-site scenarios, enumerating the HTTP query parameters id and L allowed out-of-scope access to rendered content in the website frontend. For instance, this allowed visitors to access content of an internal site by adding handcrafted query parameters to the URL of a site that was publicly available.
Solution
Update to TYPO3 versions 9.5.42 ELTS, 10.4.39 ELTS, 11.5.30, 12.4.4 that fix the problem described above.
ℹ️ Strong security defaults - Manual actions required Resolving sites by the
idandLHTTP query parameters is now denied per default. However, it is still allowed to resolve a particular page by e.g.https://example.org/?id=123&L=0- as long as thepage-id 123is in the scope of the site configured for thebase-url example.org. The new feature flagsecurity.frontend.allowInsecureSiteResolutionByQueryParameters- which is disabled per default - can be used to reactivate the previous behavior.
Credits
Thanks to Garvin Hicking who reported this issue, and to TYPO3 core & security team members Oliver Hader and Benjamin Franzke who fixed the issue.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 9.4.0&&< 9.5.42 | 9.5.42composer require typo3/cms-core:^9.5.42 |
| 🐘Packagist | typo3/cms-core | ≥ 10.0.0&&< 10.4.39 | 10.4.39composer require typo3/cms-core:^10.4.39 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.5.30 | 11.5.30composer require typo3/cms-core:^11.5.30 |
| 🐘Packagist | typo3/cms-core | ≥ 12.0.0&&< 12.4.4 | 12.4.4composer require typo3/cms-core:^12.4.4 |
Affected Products
typo3typo3Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-core to 9.5.42 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-38499 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-2023-38499 in your dependencies?
Find it across Packagist, including transitive dependencies.