On 12 May 2026, Microsoft released its largest security update of the year, fixing 120 separate vulnerabilities across Windows 10 and Windows 11. If you use a Windows computer, this update matters – and here is what you need to know in plain English.
What was the issue?
Security researchers discovered a wide range of weaknesses in Windows that could potentially allow attackers to take control of a computer, steal information, or disrupt how a machine works. The three most serious were:
A flaw in Windows network authentication that could give an attacker full control of a server without needing a password or any help from the user. A weakness in the Windows DNS system – the service that translates website addresses into connections – that could allow a malicious website to run code on your computer simply by you visiting it. A flaw in Windows GDI, the graphics system, that could be triggered just by opening a specially crafted file in Microsoft Paint.
None of these vulnerabilities were being actively exploited at the time Microsoft released the fix, which is good news. But security experts warned that attackers typically reverse-engineer patches within 24 to 48 hours of release to find ways to attack unpatched machines.
When was it fixed?
All vulnerabilities were addressed in the May 2026 Patch Tuesday update released on 12 May 2026. This update is mandatory and will be applied automatically to most Windows 11 machines that have automatic updates enabled.
What did GeiG do?
GeiG builds all Dade notebooks with Windows 11 Pro and automatic Windows Update enabled by default. This means your device will receive critical security patches automatically. We also updated our production device image on 13 May 2026 to include the May Patch Tuesday update, so all new Dade devices ship fully patched from day one.
If you are unsure whether your device has received this update, go to Settings, Windows Update, and check your update history. You should see KB5089549 listed as installed. If not, click Check for Updates to install it now.
As always, our support team is here Monday to Friday, 9am to 6pm at support@geig.co.uk.
