Microsoft 365 Copilot Chat Information Disclosure Vulnerability
Evidence indicates that Microsoft 365 Copilot Chat is affected by a security issue.
What Happened
Evidence indicates that Microsoft 365 Copilot Chat is affected by a security issue.
Why This Matters
Publisher reporting describes a concrete security event. BugSkan could not yet bind it to a CVE or affected version, so treat the source details as the current record.
Recommended Action
No confirmed vendor remediation is available in the current evidence. Confirm whether Microsoft 365 Copilot Chat is present in your environment and review the affected configuration.
Exposure
Exposure unknown
Feb 18, 2026 05:30
Exposure reason: This incident does not currently match a technology in My AI Stack.
Exploitation status: UNKNOWN
Primary entities:
Timeline
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Incident first seen
Feb 18, 2026 05:30BugSkan first recorded this incident.
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Copilot Chat bug bypasses DLP on 'Confidential' email - theregister.com
Feb 18, 2026 05:30theregister.com · Data Leak
Sources
theregister.com · Feb 18, 2026 05:30
Microsoft 365 Copilot Chat was found to bypass Data Loss Prevention (DLP) policies, summarizing emails with "confidential" sensitivity labels and exposing protected content. This vulnerability, tracked as CW1226324, stemmed from a code issue allowing Copilot to access emails in Draft and Sent folders despite configured restrictions, leading to unintended information disclosure within the chat interface.
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