Microsoft Copilot bug leaks 2FA codes

Microsoft 365 Copilot for business has a critical bug that could let attackers steal sensitive info. Security firm Varonis Threat Labs found it, named SearchLeak, tracked as CVE-2026-42824.

The bug works in three steps: attackers hide bad instructions in a link. When users click it, Copilot's AI thinks it's a search command, like 'find user emails'. Then Copilot puts private data—2FA codes, email subjects, meeting invites, OneDrive files—into image links and sends them out via Bing.

Researcher Dolev Taler says this isn't a typical system bug—it tricks the AI into trusting natural language. It affects all indexed content in a company. Microsoft fixed it and says no one has used it in real attacks yet.