Windows 11 users should pay attention, as Microsoft has released an urgent update to fix significant flaws, mainly those associated with the September 2026 Patch Tuesday. This is a mandatory update and applies to versions 26H1, 25H2, and 24H2 of the operating system.
It is worth noting that the term Patch Tuesday refers to a cycle of security updates for Windows that Microsoft usually releases on the second Tuesday of each month. The September edition was released on the 8th, through package KB5124008. After this date, various user reports emerged regarding difficulties after installing this update.
Microsoft itself admitted that package KB5124008 is causing problems with USB audio equipment, the Remote Desktop Services (RDS) component, and file sharing between Windows 11 and Linux virtual machines. Such and other issues are being addressed by updates KB5129195 (for 25H2 and 24H2) and KB5129194 (for 26H1).
Both packages are classified as 'out-of-band,' meaning they were released outside the usual Microsoft update schedule, specifically to deal with emergency occurrences. Furthermore, a privilege escalation vulnerability that was not fully corrected by Patch Tuesday was also addressed.
However, not all problems have been resolved. Flaws related to USB audio may still persist in certain devices. Additionally, issues involving File History and certain AMD graphics cards, also linked to the September Patch Tuesday, remain unresolved, as Microsoft has not yet acknowledged them.
In recent days, there has been an increase in reports from users of Lenovo and HP notebooks experiencing issues with package KB5121003 (corresponding to the August 2026 Patch Tuesday), although Microsoft has not yet issued a statement on these cases.
Package KB5129195 (or KB5129194, in the case of Windows 11 26H1) requires mandatory installation, implying that the procedure must be executed automatically. However, if the user wishes to speed up the installation, instructions are available for doing so.