Reprompt attack let hackers hijack Microsoft Copilot sessions

Reprompt attack let hackers hijack Microsoft Copilot sessions

Researchers have discovered a new attack method called “Reprompt” that exploits Microsoft’s Copilot to exfiltrate sensitive user data without detection. The vulnerability was addressed by Microsoft in a recent security update, emphasizing the importance of applying the latest patches. #MicrosoftCopilot #RepromptVulnerability

Keypoints

  • Reprompt allows attackers to infiltrate a user’s Microsoft Copilot session via malicious URL prompts.
  • The attack leverages techniques like P2P injection, double-request, and chain-request to bypass safeguards.
  • Once compromised, the attacker can continuously exfiltrate data by communicating with Copilot’s server.
  • Microsoft fixed the vulnerability in the January 2026 Patch Tuesday update, closing the security gap.
  • The attack impacts only the personal version of Copilot, not the enterprise-focused Microsoft 365 Copilot.

Read More: https://www.bleepingcomputer.com/news/security/reprompt-attack-let-hackers-hijack-microsoft-copilot-sessions/