MC1526780 - New MSRC blog: Microsoft’s response to compromised eMudhra certificate authority keys

Message Center

Discussionpowered by zap.ms

Published

Oct 27, 2026

Service

Windows

Tag

Admin impact

More information

Microsoft has published a new blog post outlining our response to the compromise of eMudhra intermediate certificate authority keys, including changes to the Windows and Microsoft Edge trust lists.

The Windows out-of-band updates are now available in the Microsoft Update Catalog. Administrators managing disconnected devices, or devices that don’t receive automatic certificate trust updates, can find more context and recommended steps in Microsoft’s response to compromised eMudhra certificate authority keys.

The following Windows updates are now available: