Critical CVSS 9.8 2026-06 archive

Executive Summary

Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.

Overview

9.8
CVSS CRITICAL
Critical
MS Severity
Not Exploited
MS Exploit Status
N/A
MS Exploit Likelihood
Category Information Disclosure
Released Jun 9 2026
Last Updated Jun 9 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known

CVSS Vector

ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 8.5

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Known Exploits

Acknowledgments

Yuval Weber with Microsoft, Shira Hoffman with Microsoft