Full Report
Researchers have uncovered a critical vulnerability (CVE-2025-29927) in Next.js middleware, allowing authorization bypass. Learn about the exploit and fixes.
Analysis Summary
# Vulnerability: Next.js Middleware Authorization Bypass
## CVE Details
- CVE ID: CVE-2025-29927
- CVSS Score: *Score is not explicitly mentioned in the text, implying a high severity but lacking a specific numerical value.* ([Severity based on description: Critical/High])
- CWE: Access Control (Implied, as it is an authorization bypass)
## Affected Systems
- Products: Next.js (Framework)
- Versions: *Specific vulnerable versions are not detailed in the summary text.*
- Configurations: Next.js applications utilizing the Middleware feature.
## Vulnerability Description
Researchers discovered a critical vulnerability within the Next.js framework's Middleware functionality that allows attackers to bypass established authorization checks. This flaw enables unauthorized access to protected routes or resources by circumventing logic intended to restrict access.
## Exploitation
- Status: *Not explicitly stated, but the high-impact description suggests potential for exploitation.*
- Complexity: *Not specified.*
- Attack Vector: *Execution relies on network requests targeting the application routes.*
## Impact
- Confidentiality: High (Potential unauthorized access to sensitive data)
- Integrity: High (Potential unauthorized modification of application state or data)
- Availability: Low to Medium (Depends on the bypassed protection mechanism)
## Remediation
### Patches
- **Immediate action recommended:** Users should consult the official Next.js advisory for the specific patched version incorporating the fix for CVE-2025-29927.
### Workarounds
- *No specific workarounds were detailed in the provided text.* Security teams should review existing middleware logic to ensure redundant authorization checks are in place outside the scope of the middleware function if possible, or restrict network access to non-public routes temporarily.
## Detection
- **Indicators of Compromise:** Look for unauthorized access attempts to pages or API endpoints that should only be accessible post-authentication. Monitoring traffic patterns for requests that successfully reach protected resources without corresponding session/authorization tokens might serve as an indicator.
- **Detection Methods and Tools:** Application security monitoring tools should be configured to log detailed authorization results from application middleware layers.
## References
- Vendor Advisory: Next.js Technical Advisory regarding CVE-2025-29927
- Relevant links:
- hxxps://hackread.com/next-js-middleware-flaw-bypass-authorization/