Microsoft Teams Authentication and Authorization Flaws

Privilege elevation in Microsoft Teams lets a remote, unauthenticated attacker gain unauthorized access across a network due to a missing authorization check (CWE-862). The maximum 10.0 CVSS rating stems from a changed scope with high confidentiality and integrity impact, meaning the flaw reaches resources beyond the initially vulnerable component. No public exploit identified at time of analysis and the issue is not listed in CISA KEV, but the perfect-score, no-precondition profile makes it a top-tier patch priority.

Privilege elevation in Microsoft Teams allows an authenticated attacker with low-level access to bypass authentication controls and gain higher privileges across a network boundary. The CVSS:3.1 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H) shows the flaw is remotely reachable, requires only low existing privileges, needs no user interaction, and crosses a security scope to compromise confidentiality and integrity of resources beyond the initially authorized context. No public exploit identified at time of analysis, and the issue is not listed in CISA KEV, but the 9.6 base score reflects the low barrier to abuse once an attacker holds any authenticated Teams foothold.

Cryptographic signature spoofing in Microsoft Teams exposes enterprise collaboration environments to unauthenticated identity impersonation over the network. The flaw, tagged as a JWT attack enabling authentication bypass, allows a remote attacker with no prior credentials to forge or tamper with token-based identity claims that Teams fails to properly verify. No active exploitation has been confirmed by CISA KEV, and no public proof-of-concept has been identified at time of analysis, though the CVSS vector (AV:N/AC:L/PR:N/UI:N) indicates a low-barrier, remotely exploitable path with high integrity impact.