Next.js version 16.x contains an improper authorization vulnerability that may allow unauthenticated users to bypass access controls.

This vulnerability involves improper authorization (CWE-285), where the framework fails to correctly enforce security constraints, allowing unauthenticated attackers to perform actions or access data they should be restricted from.

By bypassing authorization checks, an attacker could gain unauthorized access to sensitive application data or perform administrative actions without proper credentials. Given the 8.3 CVSS score, this represents a significant risk to the integrity and confidentiality of the web application, potentially leading to unauthorized data modification or exposure.

Immediate Action: Update the Next.js dependency to version 16.2.11 or later.

Proactive Monitoring: Monitor application access logs for unexpected, unauthorized requests to sensitive endpoints or API routes that should be protected.

Compensating Controls: Ensure that additional authorization logic is implemented at the application level to provide defense in depth, even if the framework vulnerability is present.

Public Exploit Available: Unknown.

Security and development teams must prioritize updating Next.js to the fixed version 16.2.11 immediately. Ensuring that security patches are applied promptly is the most effective way to prevent unauthorized access to your application resources.