🟠 High | Source: Microsoft Security Response Center
A vulnerability in Microsoft Teams allows an attacker with network access to gain elevated privileges without any prior authorisation. The flaw stems from missing authorisation checks, meaning an attacker could potentially escalate their access within an organisation’s Teams environment. This is particularly concerning given how widely Teams is deployed across enterprises for day-to-day communication and collaboration.
Security Architect’s Take: Review your network segmentation to limit lateral movement opportunities, and ensure Microsoft Teams is patched to the latest version immediately. Until patching is confirmed, consider monitoring Teams-related activity logs in Microsoft Sentinel or your SIEM for anomalous privilege changes or unexpected API calls.
Original advisory: CVE-2026-65667 Microsoft Teams Elevation of Privilege Vulnerability