Microsoft Store Office apps lose security updates after Dec 2026

Microsoft will stop delivering security updates to Microsoft Store versions of Office apps in December 2026, meaning any user who still runs Word, Excel or PowerPoint installed from the Store will be left vulnerable unless they migrate to the Click‑to‑Run (C2R) deployment model [1].

End of support timeline

Microsoft’s updated support page confirms that the Store installation type of Microsoft 365 apps will no longer receive security patches after December 2026, with feature updates already halted in October 2025 [2]. The company urges all affected users to upgrade to the Click‑to‑Run installer, which continues to receive both feature and security updates. The Office Deployment Tool, a command‑line utility, automates the detection, removal and replacement of Store apps with C2R versions, preserving licenses and settings [1].

Why Click‑to‑Run matters

Click‑to‑Run differs from the traditional Store (Appx) package by streaming the installation: users can launch an app while the remainder downloads in the background, and updates are applied directly from Microsoft’s CDN without requiring a Windows Update cycle [1]. This model also supports enterprise‑grade features such as XML configuration, multi‑user deployment, and management through Intune or Configuration Manager—capabilities the Store version lacks [2]. As Microsoft accelerates cloud‑driven enhancements like Copilot, the faster update cadence of C2R becomes essential for delivering new functionality promptly.

Impact on users and IT admins

For most home users, the transition will be largely invisible; the apps will look and behave the same, but staying on the Store version after December 2026 will expose them to unpatched vulnerabilities. Enterprise environments face a sharper impact: C2R provides granular control over update channels, shared device activation, and telemetry, aligning with the management tools that large organizations rely on [2]. The retirement of the Store model therefore clears a path for a more predictable, cloud‑managed Office ecosystem.

What to watch

• Migration progress – Monitor adoption rates of the Office Deployment Tool as Microsoft tracks the shift from Store to C2R.
• Enterprise rollout – Watch for announcements from large IT vendors (e.g., Microsoft Intune, Configuration Manager) on bulk deployment strategies.
• Feature releases – Note any new Microsoft 365 features (e.g., Copilot updates) that are delivered exclusively via Click‑to‑Run after the Store deadline.

The December 2026 cutoff underscores Microsoft’s strategic move away from the Store packaging model toward a deployment approach that better serves both rapid feature delivery and enterprise management, leaving users with a clear deadline to modernize their Office installations.