Microsoft has hustled out an out-of-band update to address a Message Queuing issue introduced by the December 2025 update.

Microsoft has confirmed that the December 2025 security updates are breaking Message Queuing (MSMQ) functionality, affecting enterprise applications and Internet Information Services (IIS) websites.

Messaging middleware for Windows NT from Microsoft. Code-named Falcon, and abbreviated MSMQ, it allows programs to send messages to other programs. It can be used to queue up transactions in a ...