CVE-2025-59020

Problem

By exploiting the defVals parameter, attackers could bypass field‑level access checks during record creation in the TYPO3 backend. This gave them the ability to insert arbitrary data into prohibited exclude fields of a database table for which the user already has write permission for a reduced set of fields.

Credits

Thanks to Daniel Windloff for reporting this issue, and to TYPO3 core & security team member Benjamin Franzke for fixing it.

References

• TYPO3-CORE-SA-2026-001

The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.

Kodem intelligence

Update to TYPO3 versions 10.4.55 ELTS, 11.5.49 ELTS, 12.4.41 LTS, 13.4.23 LTS, 14.0.2 that fix the problem described.

1. What is CVE-2025-59020? CVE-2025-59020 is a medium-severity incorrect authorization vulnerability in typo3/cms-backend (composer), affecting versions >= 14.0.0, <= 14.0.1. It is fixed in 14.0.2, 13.4.23, 12.4.41, 11.5.49, 10.4.55. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
2. Which versions of typo3/cms-backend are affected by CVE-2025-59020? typo3/cms-backend (composer) versions >= 14.0.0, <= 14.0.1 is affected.
3. Is there a fix for CVE-2025-59020? Yes. CVE-2025-59020 is fixed in 14.0.2, 13.4.23, 12.4.41, 11.5.49, 10.4.55. Upgrade to this version or later.
4. Is CVE-2025-59020 exploitable, and should I be worried? Whether CVE-2025-59020 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
5. What actually determines whether CVE-2025-59020 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.
6. How do I fix CVE-2025-59020?
   • Upgrade typo3/cms-backend to 14.0.2 or later
   • Upgrade typo3/cms-backend to 13.4.23 or later
   • Upgrade typo3/cms-backend to 12.4.41 or later
   • Upgrade typo3/cms-backend to 11.5.49 or later
   • Upgrade typo3/cms-backend to 10.4.55 or later