One‑Click Microsoft 365 Copilot Flaw (June 2026)
One‑Click Microsoft 365 Copilot Flaw (June 2026) A critical vulnerability chain —nicknamed “SearchLeak” —was disclosed on June 15, 2026 , affecting Microsoft 365 Copilot Enterprise Search. It allowed data exfiltration with just a single click on a trusted Microsoft link . What made this flaw dangerous? ✅ One click only – no prompt, no login trick, no second interaction required ✅ Legitimate Microsoft URL – bypassed phishing filters and URL protections ✅ Access to everything Copilot can see – email, files, calendar, SharePoint, OneDrive ✅ Could expose sensitive data like MFA codes, email subjects, and documents How the attack worked (simplified) The exploit combined three separate weaknesses into one chain : 1) Parameter‑to‑Prompt Injection (AI-specific flaw) Copilot accepts a q parameter in URLs for search queries Attackers embed malicious instructions inside that parameter When clicked, Copilot executes them as if the user typed them 👉 Example: a link tells Copilot to...