Microsoft Confirms Final October 2026 Deadline For Exchange Server 2016 and 2019 Security Updates
Microsoft has confirmed that the final deadline for security updates for Exchange Server 2016 and 2019 is October 2026, with no further extensions planned. Organizations are urged to migrate to Exchange Server Subscription Edition or Microsoft 365 to avoid security vulnerabilities.
Why it matters
This creates a hard security deadline for businesses, forcing a transition to newer platforms to maintain data protection and compliance.
Microsoft has confirmed that security updates for Exchange Server 2016 and Exchange Server 2019 will permanently end after October 2026, ruling out another extension to the temporary Extended Security Update programme protecting organisations that have not yet completed their migrations.
The decision establishes a final deadline for businesses still operating either product. Once the programme expires, Microsoft will no longer release vulnerability fixes for Exchange 2016 or 2019—even for organisations that purchased the second period of ESU coverage.
Microsoft introduced the temporary programme after both server releases reached their formal end of support on October 14, 2025. It was intended to provide a short security bridge for organisations that could not move to Exchange Server Subscription Edition or Exchange Online before the lifecycle deadline.
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