Microsoft Authenticator Flaw Let Permissionless Android Apps Steal Work Account Tokens
Summary: Microsoft fixed a flaw in Authenticator for Android, tracked as CVE-2026-80097 and rated 8.6 on the CVSS scale, that let a permissionless malicious app pose as Teams and obtain sign-in tokens for a victim's work account. Enclave researcher Ofek Levin found that Authenticator's AccountChooserActivity built token requests from attacker-supplied values, and a signature check passed because the impersonated app was genuinely installed; the fix is Authenticator version 6.2606.4246.
Why it matters: In Enclave's tests, the tokens returned Microsoft Graph permissions to read and send mail, read and write files, and read and write calendars for the work account signed into Authenticator on that device. Microsoft's advisory does not say whether updating cancels a token a malicious app may already hold, so that question is unresolved.
Read the original at The Hacker News ↗
- Topics
- Vulnerabilities & Patching
- Mentions
- CVE-2026-80097
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