TYPO3 vulnerable to Cross-Site Scripting in ShowImageController

TYPO3 is an enterprise content management system. Starting in version 9.0.0 and prior to versions 9.5.48 ELTS, 10.4.45 ELTS, 11.5.37 LTS, 12.4.15 LTS, and 13.1.1, failing to properly encode user-controlled values in file entities, the `ShowImageController` (`_eID tx_cms_showpic_`) is vulnerable to cross-site scripting. Exploiting this vulnerability requires a valid backend user account with access to file entities. TYPO3 versions 9.5.48 ELTS, 10.4.45 ELTS, 11.5.37 LTS, 12.4.15 LTS, 13.1.1 fix the problem described.