GHSA-f9hr-7cfq-mjg2 is a high-severity (CVSS 8.8) vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.
TYPO3 Arbitrary Code Execution via File List Module
Real-World Exposure
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
Due to missing file extensions in $GLOBALS['TYPO3_CONF_VARS']['BE'][‘fileDenyPattern’], backend users are allowed to upload *.phar, *.shtml, *.pl or *.cgi files which can be executed in certain web server setups. A valid backend user account is needed in order to exploit this vulnerability.
Derivatives of Debian GNU Linux are handling *.phar files as PHP applications since PHP 7.1 (for unofficial packages) and PHP 7.2 (for official packages).
The file extension *.shtml is bound to server side includes which are not enabled per default in most common Linux based distributions. File extension *.pl and *.cgi require additional handlers to be configured which is also not the case in most common distributions (except for /cgi-bin/ location).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 8.0.0&&< 8.7.23 | 8.7.23composer require typo3/cms-core:^8.7.23 |
| 🐘Packagist | typo3/cms-core | ≥ 9.0.0&&< 9.5.4 | 9.5.4composer require typo3/cms-core:^9.5.4 |
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 8.7.23 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f9hr-7cfq-mjg2 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-f9hr-7cfq-mjg2 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-f9hr-7cfq-mjg2. 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-f9hr-7cfq-mjg2 in your dependencies?
O3 Security finds GHSA-f9hr-7cfq-mjg2 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.