CVE-2025-53770 | Microsoft SharePoint Enterprise Server 2016/2019/Subscription Edition HTTP Header /_layouts/SignOut.aspx Referer ToolShell deserialization (EUVD-2025-21981 / EDB-52405)
A vulnerability classified as very critical was found in Microsoft SharePoint Enterprise Server 2016/2019/Subscription Edition. This affects an unknown part of the file /_layouts/SignOut.aspx of the component HTTP Header Handler. The manipulation of the argument Referer leads to deserialization.
This vulnerability is uniquely identified as CVE-2025-53770. It is possible to initiate the attack remotely. Furthermore, there is an exploit available.
It is recommended to upgrade the affected component.