Quantum Secular Labs / Blog / Advisories
CVE-2026-65667: Microsoft Teams: Privilege escalation
CVE-2026-65667 is rated critical with a CVSS v3.1 base score of 10.0 and affects Microsoft Teams. Per its scoring, it can be exploited over the network, without authentication, without any user interaction.
Vulnerability description
Missing authorization in Microsoft Teams allows an unauthorized attacker to elevate privileges over a network.
Severity breakdown
CVSS v3.1 10.0: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
- Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
- Attack complexity: Low. No special conditions; the attack can be repeated reliably.
- Privileges required: None. No account or prior access is needed.
- User interaction: None. No action from any user is needed.
- Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
- Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
- Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
- Availability impact: None. No effect on availability.
Underlying weakness
CWE-862: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Affected products
- Microsoft Teams: all versions listed by NVD