Quantum Secular Labs / Blog / Advisories
CVE-2026-56163: Microsoft Azure Kubernetes Service: Authentication bypass
CVE-2026-56163 is rated critical with a CVSS v3.1 base score of 10.0 and affects Microsoft Azure Kubernetes Service. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.
Vulnerability description
Missing authentication for critical function in Microsoft Azure Kubernetes Service 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:H
- 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: High. Total loss of availability; the component can be shut down.
Underlying weakness
CWE-306: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Affected products
- Microsoft Azure Kubernetes Service: all versions listed by NVD