Backend users with write access to the form_definition database table were able to directly create, update, or delete form definition records via DataHandler, bypassing the Form Framework's persistence validation and permission checks. This allowed injecting arbitrary form configurations, re-enabling attack vectors originally addressed in TYPO3-CORE-SA-2018-003, including SQL injection and privilege escalation. This issue affects TYPO3 CMS versions 14.0.0-14.3.2.

Affected: Packagist: typo3/cms-core, Packagist: typo3/cms-form

### Problem Backend users with write access to the `form_definition` database table were able to directly create, update, or delete form definition records via `DataHandler`, bypassing the Form Framework's persistence validation and permission checks. This allowed injecting arbitrary form configurations, re-enabling attack vectors originally addressed in [TYPO3-CORE-SA-2018-003](https://typo3.org/security/advisory/typo3-core-sa-2018-003), including SQL injection and privilege escalation.

### Solution Update to TYPO3 version 14.3.3 LTS that fixes the problem described.

### Credits TYPO3 CMS thanks Selçuk Güney for reporting this issue, and to TYPO3 core & security team member Oliver Hader for fixing it.

### Resources * [TYPO3-CORE-SA-2026-017](https://typo3.org/security/advisory/typo3-core-sa-2026-017)

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