Summary
Problem
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.
Credits
TYPO3 CMS thanks Wolfgang Klinger for reporting this issue, and to TYPO3 core & security team member Oliver Hader for fixing it.
Resources
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Update to TYPO3 versions 10.4.57 ELTS, 11.5.51 ELTS, 12.4.46 ELTS, 13.4.31 LTS, 14.3.3 LTS that fix the problem described.
Frequently Asked Questions
- What is CVE-2026-49738? CVE-2026-49738 is a low-severity path traversal vulnerability in typo3/cms-core (composer), affecting versions < 10.4.57. It is fixed in 10.4.57, 11.5.51, 12.4.46, 13.4.31, 14.3.3. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of typo3/cms-core are affected by CVE-2026-49738? typo3/cms-core (composer) versions < 10.4.57 is affected.
- Is there a fix for CVE-2026-49738? Yes. CVE-2026-49738 is fixed in 10.4.57, 11.5.51, 12.4.46, 13.4.31, 14.3.3. Upgrade to this version or later.
- Is CVE-2026-49738 exploitable, and should I be worried? Whether CVE-2026-49738 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-49738 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-49738?
- Upgrade
typo3/cms-coreto 10.4.57 or later - Upgrade
typo3/cms-coreto 11.5.51 or later - Upgrade
typo3/cms-coreto 12.4.46 or later - Upgrade
typo3/cms-coreto 13.4.31 or later - Upgrade
typo3/cms-coreto 14.3.3 or later
- Upgrade