Microsoft’s Exchange team published a short but important Hotfix Update (HU) rollup for September 2025 that is aimed at fixing a non‑security issue in earlier updates and, crucially, preserves support for the dedicated Exchange hybrid application workflow introduced earlier in 2025 — the update...
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cve-2025-53786
dedicatedhybridapp
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ews
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hotfix update
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september 2025
service principal
windows update
Microsoft’s Exchange team has taken a decisive step toward finally letting organizations retire the last Exchange server in hybrid environments by adding cloud-managed remote mailbox support — a per-mailbox “flip-the-switch” that transfers Exchange attribute authority to Exchange Online while...
Microsoft's updated Exchange hybrid guidance — and a last‑minute change to the enforcement cadence — should be on every hybrid admin’s radar: the Exchange team has expanded the push to migrate hybrid traffic away from the long‑standing Exchange Online shared service principal into a tenant‑owned...
april 2025 hotfix
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cve-2025-53786
dedicatedhybridapp
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hybrid coexistence
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phased enforcement
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security hardening
service principal
Microsoft’s Exchange team has given hybrid administrators a clear-but-urgent migration mandate: switch to the dedicated Exchange hybrid app and update on‑prem servers now, or face temporary disruptions in September and October followed by a permanent enforcement that will stop rich coexistence...