Microsoft Defender for Office 365 introduces prompt injection protection to detect and block malicious email content targeting AI assistants. High confidence threats are auto-quarantined. Available to Plan 2 and Microsoft 365 E5 users, enabled by default from early July 2026. No action required; review workflows and inform teams.
Day in brief
Microsoft Defender for Office 365: Prompt injection protection for email
9 July 2026 recorded 1 tracked Microsoft Defender documentation change and 1 relevant Message Center announcement. The most active areas were Defender XDR.
- Microsoft Defender for Office 365: Prompt injection protection for email
Defender XDR · Email and collaborationMicrosoft Defender for Office 365 introduces prompt injection protection to detect and block malicious email content targeting AI assistants. High confidence threats are auto-quarantined. Available to Plan 2 and Microsoft 365 E5 users, enabled by default from early July 2026. No action required; review workflows and inform teams.
This period briefing was assembled from the tracked Microsoft Learn and Message Center changes.
1 update