Microsoft 365 Copilot at a glance
Microsoft published CVE-2026-26133 on March 12, 2026: an AI command injection in Microsoft 365 Copilot where a malicious email could make Copilot show authoritative-looking phishing messages. It is rated Important (CVSS 7.1), and Microsoft lists fixed builds of Copilot, Outlook, Teams, Office, and Edge apps.
Microsoft 365 Copilot: status
- Affected
- Microsoft 365 Copilot for iOS before 2.107.2 and for Android before 16.0.19815.10000
- Outlook for iOS, Android, and Mac before 5.2605; Teams for iOS before 8.3.1
- Copilot-enabled Word, Excel, PowerPoint, OneNote, Loop, Power BI, and Edge mobile apps (fixed builds in Microsoft's update guide)
- CVE identifiers
- Status as of
- Discovered by
- Andi Ahmeti (Permiso Security)
What changed with Microsoft 365 Copilot
Microsoft's FAQ says an attacker could send an email crafted so that Copilot, when processing it, presents official-looking messages that push the user to click links leading to data exfiltration or a malicious site. Microsoft classifies the issue as information disclosure that requires user interaction, credits Andi Ahmeti of Permiso Security, and reported no public disclosure or exploitation at release.
The update guide lists fixed builds across Copilot-enabled apps, including Microsoft 365 Copilot for iOS 2.107.2 and for Android 16.0.19815.10000, Outlook for iOS, Android, and Mac 5.2605, Teams for iOS 8.3.1, plus Word, Excel, PowerPoint, OneNote, Loop, Power BI, and Edge mobile apps, and marks customer action as required.
How to fix it: Microsoft 365 Copilot
1. Update
Update Copilot-enabled Microsoft 365, Outlook, Teams, Office, and Edge apps to the fixed builds listed in Microsoft's update guide.
msrc.microsoft.com (opens in a new tab)
Advisories
- Microsoft Security Update Guide CVE-2026-26133 (opens in a new tab)msrc.microsoft.com
- NVD CVE-2026-26133 (opens in a new tab)nvd.nist.gov
Why Microsoft 365 Copilot matters for businesses
Indirect prompt injection turns an assistant's credibility into a phishing channel, because people tend to trust a Copilot summary more than the raw email. Keep Copilot-enabled apps current through device management, and teach staff that security alerts or links inside AI summaries deserve the same skepticism as the message itself.
Sources for this story
- M365 Copilot Information Disclosure Vulnerability (CVE-2026-26133) (opens in a new tab)Official
Microsoft Security Response Center · msrc.microsoft.com
- CVE-2026-26133 (opens in a new tab)Official
NIST National Vulnerability Database · nvd.nist.gov
Last verified: . IA Compa summarizes public announcements for business readers. We are not affiliated with the companies mentioned. Always confirm details, pricing, and availability with the official source.
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- #cve
- #microsoft-365-copilot
- #prompt-injection
- #phishing
- #microsoft
