E-Mails exported as PDF were stored in a cache that did not consider specific session information for the related user account. Users of the same service node could access other users E-Mails in case they were exported as PDF for a brief moment until caches were cleared. Successful exploitation requires good timing and modification of multiple request parameters. Please deploy the provided updates and patch releases. The cache for PDF exports now takes user session information into consideration when performing authorization decisions. No publicly available exploits are known.