Microsoftは、企業向け有償サービス「Microsoft 365 Copilot」の「Copilot Chat」がDLPポリシーや機密ラベルを回避し、顧客の機密メールを不適切に要約していた問題を認めた。送信済みや下書きフォルダの機密メールがインデックス化されたことが原因。1月下旬から発生し、現在は修正プログラムを展開中だが、詳細な影響規模や監査ログは公表されていない。

Microsoft is expanding data loss prevention (DLP) controls to block the Microsoft 365 Copilot AI assistant from processing ...

Microsoft expands DLP controls to prevent Copilot from processing confidential Office files across local devices, SharePoint, and OneDrive.

Microsoft says a Microsoft 365 Copilot bug has been causing the AI assistant to summarize confidential emails since late ...

image:image:generatedaatWhiskマイクロソフトが、Microsoft365CopilotChatにバグがあることをOffice管理者向けの通知で認めました。「機密（Confidential）」の秘密度ラベルが設定されているに ...

Microsoft 365 Copilot bug let AI summarize confidential emails despite Data Loss Prevention rules. What it means for your data and safety.

Microsoft has patched a Copilot bug that exposed confidential Outlook emails and expanded DLP controls to cover all storage locations via Microsoft Purview.

Microsoft has confirmed that a bug in its Office suite allowed Copilot AI to surface private email content from users’ ...

M365 Copilot Chat was summarizing your emails, whether you granted it access or not. This bug affected Sent and Draft folders ...

Microsoft confirms a Copilot bug that summarized confidential emails despite DLP protections. Fix is rolling out, impact remains unclear.