A stored cross-site-scripting security issue in the save page feature was reported by Ngo Van Thien, Sun* Inc.
The issue affects all UliCMS Versions.
The security hotfix FixPageControllerXSS was released for UliCMS 2019.4 and 2020.1.
If you still use an older release of UliCMS you should upgrade to a supported version and then install the patch.
The upcoming release 2020.2 will include the fix at release state.