The Pimcore Admin Classic Bundle provides a backend UI for Pimcore. Prior to version 1.2.0, a cross-site scripting vulnerability has the potential to steal a user's cookie and gain unauthorized access to that user's account through the stolen cookie or redirect users to other malicious sites. Users should upgrade to version 1.2.0 to receive a patch or, as a workaround, apply the patch manually.
https://github.com/pimcore/pimcore/commit/757375677dc83a44c6c22f26d97452cc5cda5d7c
https://github.com/pimcore/admin-ui-classic-bundle/security/advisories/GHSA-jfxw-6c5v-c42f
https://github.com/pimcore/admin-ui-classic-bundle/commit/19fda2e86557c2ed4978316104de5ccdaa66d8b9