Microsoft says it has resolved a Windows 11 bug that caused some commercial systems to fail to boot with an "UNMOUNTABLE_BOOT_VOLUME" error after installing recent security updates, with the fix delivered in the February 2026 Patch Tuesday update. [...]

Microsoft has fixed a "remote code execution" vulnerability in Windows 11 Notepad that allowed attackers to execute local or remote programs by tricking users into clicking specially crafted Markdown links, without displaying any Windows security warnings. [...]

The AgreeTo add-in for Outlook has been hijacked and turned into a phishing kit that stole more than 4,000 Microsoft account credentials. [...]

After a decade and a half of service, the current certificates will expire, and new ones will be rolled out.

The post Microsoft to Refresh Windows Secure Boot Certificates in June 2026 appeared first on SecurityWeek.

Microsoft has announced Windows 11 26H1, but it's not for existing PCs. Instead, it will ship on devices with Snapdragon X2 processors and possibly other rumored ARM chips.w [...]

Microsoft has released the Windows 10 KB5075912 extended security update to fix February 2026 Patch Tuesday vulnerabilities, including six zero-days, and continue rolling out replacements for expiring Secure Boot certificates. [...]

Today is Microsoft's February 2026 Patch Tuesday with security updates for 58 flaws, including 6 actively exploited and three publicly disclosed zero-day vulnerabilities. [...]

Microsoft has released Windows 11 KB5077181 and KB5075941 cumulative updates for versions 25H2/24H2 and 23H2 to fix security vulnerabilities, bugs, and add new features. [...]

Microsoft has begun rolling out updated Secure Boot certificates through monthly Windows updates to replace the original 2011 certificates that will expire in late June 2026. [...]

Microsoft is investigating an outage that blocks some administrators with business or enterprise subscriptions from accessing the Microsoft 365 admin center. [...]

Microsoft wants to introduce smartphone-style app permission prompts in Windows 11 to request user consent before apps can access sensitive resources such as files, cameras, and microphones. [...]

Microsoft is investigating an ongoing Exchange Online issue that mistakenly flags legitimate emails as phishing and quarantines them. [...]

Microsoft announced today that the Exchange Web Services (EWS) API for Exchange Online will be shut down in April 2027, after nearly 20 years. [...]

Microsoft has started rolling out built-in Sysmon functionality to some Windows 11 systems enrolled in the Windows Insider program. [...]

Microsoft gives the FBI the ability to decrypt BitLocker in response to court orders: about twenty times per year.

It’s possible for users to store those keys on a device they own, but Microsoft also recommends BitLocker users store their keys on its servers for convenience. While that means someone can access their data if they forget their password, or if repeated failed attempts to login lock the device, it also makes them vulnerable to law enforcement subpoenas and warrants.

Microsoft has confirmed that a known issue preventing some Windows 11 devices from shutting down also affects Windows 10 systems with Virtual Secure Mode (VSM) enabled. [...]

Microsoft has fixed a known issue that was causing the password sign-in option to disappear from the lock screen options after installing Windows 11 updates released since August 2025. [...]

Microsoft announced that it will disable the 30-year-old NTLM authentication protocol by default in upcoming Windows releases due to security vulnerabilities that expose organizations to cyberattacks. [...]

Microsoft has fixed a known issue that prevented Microsoft 365 customers from opening encrypted emails in classic Outlook after a recent update. [...]

Microsoft has released the KB5074105 preview cumulative update for Windows 11 systems, which includes 32 changes, including fixes for sign-in, boot, and activation issues. [...]