Microsoft Teams Vulnerability Allows Malware Delivery Through ...
A critical vulnerability in Microsoft Teams allows attackers to deliver malware through specially crafted meeting invitations.
Executive Summary
CVE-2026-21234 allows attackers to deliver malicious payloads through Teams meeting invitations that execute when a user previews the invite—no clicks required. The vulnerability exploits how Teams processes rich content in meeting descriptions.
Technical Analysis
Attackers embed specially crafted HTML and JavaScript that escapes the Teams rendering sandbox. Because Teams has access to Microsoft 365 authentication tokens, successful exploitation can cascade into broader compromise. Attackers deploy infostealers harvesting cached credentials and browser cookies.
Remediation
Apply February Patch Tuesday updates. Block external meeting invitations or implement additional filtering for Teams meeting invites from unknown senders.
References
- Microsoft Security Advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21234
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