​Microsoft is working to resolve a bug that causes Defender for Endpoint to incorrectly tag some devices' BIOS (Basic Input/Output System) firmware as outdated, prompting users to update it. In a service alert seen by BleepingComputer, Redmond said that this known issue affects Dell devices and is caused by a Defender for Endpoint logic bug. "Microsoft have identified that a code bug in the Microsoft Defender for Endpoint logic that fetches vulnerabilities for Dell devices is causing impact," the company said earlier today. "Your organization is affected by this event, and some users receiving Microsoft Defender for Endpoint alerts for the BIOS version of their Dell devices are impacted." Earlier this month, Redmond fixed another false positive that was causing an anti-spam service to erroneously block Microsoft Teams and Exchange Online users from opening URLs.