By Guru Baran
Publication Date: 2025-12-23 16:54:00
Microsoft is strengthening the security posture of enterprise collaboration by automatically enabling critical messaging safety features in Microsoft Teams.
According to a new administrative update, the company will switch several protective settings to “On” by default starting January 12, 2026, affecting tenants who rely on standard configurations.
The initiative represents a shift toward “secure-by-default” principles, aiming to reduce the attack surface for organizations that may have overlooked manual security hardening.
As detailed in administrative advisories MC1148540, MC1148539, and MC1147984, the update targets the Messaging Safety section of the Teams Admin Center.
What Is Changing?
For tenants that have not modified their messaging safety settings, three specific protections will be automatically activated:
- Weaponizable File Type Protection: This feature blocks the transmission of file extensions known to be high-risk…
