GHSA-jq6g-4v5m-wm9r 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.
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 GHSA-jq6g-4v5m-wm9r.
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-jq6g-4v5m-wm9r 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 378,567 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
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 |
Detection & 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 GHSA-jq6g-4v5m-wm9r 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-jq6g-4v5m-wm9r can be triaged on real exposure rather than presence alone.
Tailored to GHSA-jq6g-4v5m-wm9r. 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-jq6g-4v5m-wm9r in your dependencies?
O3 Security finds GHSA-jq6g-4v5m-wm9r across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.