Varonis found a “Reprompt” attack that let a single link hijack Microsoft Copilot Personal sessions and exfiltrate data; Microsoft patched it in January 2026.

Modern economies run on networks that are expected to be always on, always secure, and increasingly autonomous. Hospitals rely on them for connected medical dev ...

Reprompt impacted Microsoft Copilot Personal and, according to the team, gave "threat actors an invisible entry point to perform a data‑exfiltration chain that bypasses enterprise security controls ...