Microsoft recently announced that a critical security vulnerability had been discovered in Exchange Server (CVE-2026-42897). Until a regular security update becomes available, the vendor has recommended temporary security measures, which we have implemented on our mail servers.

We would like to inform you about the known issues and show you how you can continue to work without restrictions.

1. Problem: Embedded images are not displayed
Images and screenshots inserted directly into the email text may currently not appear in the standard OWA view. The content is still present—it is simply being blocked by the system.

What you need to do:

• For recipients: If you know the sender and the email is trustworthy, open the email and click “Reply” or “Forward”—the images will then usually be visible again in the editing window.
• Use local programs: Use the installed Outlook client (Windows/macOS) or another local email app (e.g., Thunderbird, Apple Mail). These are not affected by the restriction.
• For senders: If you send emails with graphics or screenshots yourself: For now, please include them as file attachments rather than directly in the text.

2. Problem: OWA Light can no longer be accessed
Users of the simplified “OWA Light” view may currently be unable to log in to the web portal. This setting cannot be changed on your own while it is blocked—we’d be happy to reset it for you.

What you need to do: Simply send a short email to help@it.tuwien.ac.at, opens in new window with the subject line:
“Please disable OWA Light mode for my account.”
The upTUdate team will take care of the rest, and OWA will then be available to you again in the standard interface.

When will the issue be resolved?
Unfortunately, an immediate solution is not within our control—we are awaiting a corrective update from Microsoft. As soon as it becomes available, we will implement it immediately.

Thank you for your understanding and your cooperation in protecting the university’s IT infrastructure. Please feel free to contact us at any time with questions.

Your CIT Mail & AD Team
Campus IT | Technische Universität Wien