Important CVSS 4.4 EPSS 0.00249 2026-05 archive

Executive Summary

Improper access control in M365 Copilot allows an authorized attacker to perform spoofing locally.

Overview

4.4
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Exploitation Unlikely
MS Exploit Likelihood
Category Spoofing
Released May 12 2026
Last Updated May 12 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.00249 — 0.15869 percentile
NVD CVSS 4.4 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
Low
INTEGRITY
Low
AVAILABILITY
None
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 3.9

EPSS Score

0.00249
probability of exploitation in the next 30 days
0.15869 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

6 affected products
Product KB Article Severity Impact Restart Required
Microsoft 365 Copilot for Android Release Notes (Security Update) Important Spoofing Maybe
Microsoft Excel for Android Release Notes (Security Update) Important Spoofing Maybe
Microsoft Loop for Android Release Notes (Security Update) Important Spoofing Maybe
Microsoft OneNote for Android Release Notes (Security Update) Important Spoofing Maybe
Microsoft PowerPoint for Android Release Notes (Security Update) Important Spoofing Maybe
Microsoft Word for Android Release Notes (Security Update) Important Spoofing Maybe

Patches

1 patch
Article Type Restart
Release Notes Security Update Maybe

Known Exploits

Acknowledgments