CVE-2026-49738
CVE-2026-49738 is a Path Traversal vulnerability in typo3/cms-core. O3 Security confirms whether CVE-2026-49738 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
TYPO3 CMS - Broken Access Control in File Abstraction Layer
Blast Radius
typo3/cms-core🐘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
The path allowance check in GeneralUtility::isAllowedAbsPath() performed a plain string prefix comparison without requiring a directory separator boundary, causing a path like /var/www/html-other/secret.yaml to be incorrectly accepted as valid when the project root was /var/www/html. Administrator users with access to the File Abstraction Layer were able to create new file storage definitions pointing to directories outside the project root, bypassing this path check. This issue affects TYPO3 CMS versions before 10.4.57, 11.0.0-11.5.50, 12.0.0-12.4.45, 13.0.0-13.4.30 and 14.0.0-14.3.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | all versions | 10.4.57 |
| 🐘Packagist | typo3/cms-core | ≥ 11.0.0&&< 11.5.51 | 11.5.51 |
| 🐘Packagist | typo3/cms-core | ≥ 12.0.0&&< 12.4.46 | 12.4.46 |
| 🐘Packagist | typo3/cms-core | ≥ 13.0.0&&< 13.4.31 | 13.4.31 |
| 🐘Packagist | typo3/cms-core | ≥ 14.0.0&&< 14.3.3 | 14.3.3 |
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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update typo3/cms-core to 10.4.57 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49738 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 pinpoints whether CVE-2026-49738 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-49738. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-49738 in your dependencies?
O3 detects CVE-2026-49738 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.