Microsoft: KB5120998 mouse reset bug affects only non-English PCs
Microsoft: KB5120998 mouse reset bug affects only non-English PCs. Microsoft has confirmed that desktop settings are lost or reset on some Windows devices after installing the KB5120998 August 2026 preview update.
What happened
Microsoft: KB5120998 mouse reset bug affects only non-English PCs. Microsoft has confirmed that desktop settings are lost or reset on some Windows devices after installing the KB5120998 August 2026 preview update. Microsoft says a known issue that reverts mouse settings after installing the KB5120998 August 2026 preview update affects only non-English Windows 11 systems.
The public reporting does not establish a confirmed attacker or definitive root cause. Microsoft says KB5120998 Windows update resets desktop settings.
Editorial note: this News Brief follows the available evidence and adds length only when additional facts or useful context are available. Where public reporting does not establish a specific victim sequence, CyberDeltaForce does not present one as fact.
What the reporting and advisory establish
Microsoft says a known issue that reverts mouse settings after installing the KB5120998 August 2026 preview update affects only non-English Windows 11 systems.
Microsoft: KB5120998 mouse reset bug affects only non-English PCs
Microsoft has confirmed that desktop settings are lost or reset on some Windows devices after installing the KB5120998 August 2026 preview update.
What this means for your environment
Move from the published facts to the technical path, exposure conditions and defensive decisions that matter in a real environment.
Why this matters to you
The significance depends on whether the organizations, technologies or threat behavior in this story intersect with your environment. The useful next step is to compare the reported facts with your own exposure, suppliers and current threat model.
Does this deserve attention in my environment?
Check the conditions below against your use of Windows.
Select the conditions that are true in your environment. Leaving a condition unselected does not mean you are safe — it only means you have not marked it as applicable.
- Check whether the organizations, technologies or suppliers in the story are relevant to your environment.
- Review the retained primary source and any vendor or government guidance before changing controls.
- Increase monitoring if the reporting indicates active exploitation, material disruption or a threat path you use.
Sources & References
Original reporting and technical references are kept here for readers who want to verify the facts. Publisher names stay out of the reading flow above.