TYPO3-CORE-SA-2025-018: Denial of Service in TYPO3 Bookmark Toolbar

Categories: Development, TYPO3 CMS Created by Oliver Hader
It has been discovered that TYPO3 CMS is susceptible to denial of service.


Problem Description

Due to insufficient input validation, manipulated data saved in the bookmark toolbar of the backend user interface causes a general error state, blocking further access to the interface. Exploiting this vulnerability requires an administrator-level backend user account.

Solution

Update to TYPO3 versions 11.5.48 ELTS, 12.4.37 LTS, 13.4.18 LTS that fix the problem described.

Credits

Thanks to Jakub Świes for reporting this issue, and to TYPO3 core & security team member Oliver Hader for fixing it.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.

General Note

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