Critical CVSS 9.3 EPSS 0.00531 2026-07 archive

Executive Summary

Url redirection to untrusted site ('open redirect') in M365 Copilot allows an unauthorized attacker to elevate privileges over a network.

Overview

9.3
CVSS CRITICAL
Critical
MS Severity
Not Exploited
MS Exploit Status
N/A
MS Exploit Likelihood
Category Elevation of Privilege
Released Jul 14 2026
Last Updated Jul 14 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.00531 — 0.41148 percentile

CVSS Vector

ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
SCOPE
Changed
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
None
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 8.1

EPSS Score

0.00531
probability of exploitation in the next 30 days
0.41148 percentile - updated 2026-07-14
View on FIRST.org

Known Exploits

Acknowledgments

Vaibhavi Kalgutkar with Microsoft, Dan Reimer with Microsoft, Henrique Pereira with Microsoft