CVE-2026-41100: Microsoft 365 Copilot for Android Spoofing Vulnerability

Severity: medium (CVSS 4.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-12 · updated 2026-10-26
Weakness: CWE-284

Description

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

Affected products

Microsoft 365 Copilot: before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft 365 Copilot for Android: from 1.0 before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft Excel for Android: from 16.0.0.0 before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft Loop for Android: from 1.0.0 before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft OneNote for Android: from 16.0.1 before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft PowerPoint for Android: from 16.0.0.0 before 16.0.19822.20190 — fixed in 16.0.19822.20190
Microsoft Word for Android: from 16.0.0.0 before 16.0.19822.20190 — fixed in 16.0.19822.20190

How to fix

Upgrade to a fixed version: Microsoft 365 Copilot 16.0.19822.20190; Microsoft 365 Copilot for Android 16.0.19822.20190; Microsoft Excel for Android 16.0.19822.20190; Microsoft Loop for Android 16.0.19822.20190; Microsoft OneNote for Android 16.0.19822.20190; Microsoft PowerPoint for Android 16.0.19822.20190; Microsoft Word for Android 16.0.19822.20190. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41100

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