Microsoft Exchange Server SE CU1 Update Delayed: What You Need to Know

Microsoft has officially delayed the release of the first Cumulative Update (CU1) for Exchange Server Subscription Edition (SE) until the second half of 2025. According to reports from technical outlets including BornCity and WinFuture, Microsoft moved the release window to the second half of the year without providing a granular roadmap. Information circulating among industry observers indicates that a specific bug—identified as a “KI-Bug”—necessitated a pause in the release cycle. Microsoft has not provided further updates regarding the status of the bug-fixing process or a revised release candidate, leaving the timeline to the second half of 2025.