Microsoft confirmed a bug in its Copilot Chat feature allowed the AI to read and summarize customers’ confidential emails without permission. The vulnerability, tracked as CW1226324, has been active since January. It bypassed data loss prevention (DLP) policies, meaning emails labeled as “confidential” were processed by Microsoft 365 Copilot Chat despite restrictions meant to block sensitive information from entering the large language model.
The issue affects paying Microsoft 365 customers using the AI-powered chat feature within Office software products, including Word, Excel, and PowerPoint. Bleeping Computer first reported the bug, which Microsoft later confirmed. The tech giant began rolling out a fix for the vulnerability earlier in February. Microsoft has not disclosed the number of customers affected by the breach.
Separately, the European Parliament’s IT department has blocked built-in AI features on work-issued devices. Officials cited concerns that the AI tools could potentially upload confidential correspondence to the cloud.
