Impact

An authenticated user with write access on a restricted set of paths can update a page outside the allowed paths by specifying a different target page ID while keeping the path intact. The access control incorrectly check the path access against the user-provided values instead of the actual path associated to the page ID.

Patches

Commit 411802e fixes this vulnerability by checking access control on the path associated with the page ID instead of the user-provided value. When the path is different than the current value, a second access control check is then performed on the user-provided path before the move operation.

Thanks to @rubikscraft for reporting this vulnerability.