CVE-2021-21358: TYPO3

Medium severity, CVSS 5.4. EPSS: 0.9% chance of exploitation in the next 30 days.

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that the Form Designer backend module of the Form Framework is vulnerable to cross-site scripting. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1.

Affected products

• TYPO3 TYPO3: from 10.2.0, before 10.4.14 (fixed in 10.4.14); from 11.0.0, before 11.1.1 (fixed in 11.1.1)

Published 2021-03-23. Last modified 2026-06-17.