Microsoft has fixed a flaw in its Authenticator app for Android that let a malicious app with no permissions pose as a trusted Microsoft app, such as Teams, and collect sign-in tokens for a victim’s work account.

Microsoft tracks the flaw as CVE-2026–80097 and fixed it in Authenticator for Android version 6.2606.4246, so anyone using the app should update.

In the researchers’ tests, the tokens gave full access to the account’s email, files, and calendar. Microsoft says exploitation also needs the victim to complete a sign-in step in Authenticator, and that the flaw has not been used in attacks.