Microsoft says bug causes Copilot to summarize confidential emails
Summary
Microsoft discovered a bug in Microsoft 365 Copilot (an AI assistant integrated into Office apps) that caused it to summarize confidential emails since late January, even though those emails had sensitivity labels (tags marking them as restricted) and data loss prevention policies (DLP, security rules that prevent sensitive data from leaving an organization) were set up to block this. A code error was allowing emails in Sent Items and Drafts folders to be processed by Copilot despite the confidentiality protections.
Solution / Mitigation
Microsoft began rolling out a fix in early February and continued monitoring the deployment as of the article date, reaching out to affected users to verify the fix was working.
Classification
Affected Vendors
Related Issues
Original source: https://www.bleepingcomputer.com/news/microsoft/microsoft-says-bug-causes-copilot-to-summarize-confidential-emails/
First tracked: February 18, 2026 at 11:00 AM
Classified by LLM (prompt v3) · confidence: 92%