666ghj MiroFish REST API Authentication Bypass (CVE-2026-7042)

A critical authentication bypass vulnerability, tracked as CVE-2026-7042, has been identified in 666ghj MiroFish software up to version 0.1.2. The vulnerability lies within the create_app function of the backend/app/__init__.py file, which manages the REST API Endpoint. A remote attacker can exploit this flaw by manipulating specific parameters within API requests, effectively bypassing authentication mechanisms. This allows unauthorized access to sensitive functionalities and data. Public exploits are available, increasing the risk of widespread exploitation. The vendor was notified, but has not yet responded.

Attack Chain

1. The attacker identifies a vulnerable MiroFish instance running version 0.1.2 or earlier.
2. The attacker crafts a malicious HTTP request targeting the REST API Endpoint.
3. The crafted request manipulates parameters intended for the create_app function, specifically designed to bypass authentication checks.
4. The vulnerable create_app function fails to properly validate the request due to the missing authentication check.
5. The application grants unauthorized access to protected resources or functionalities.
6. The attacker performs unauthorized actions, such as data exfiltration, modification, or deletion, depending on the exposed API endpoints.
7. The attacker leverages the initial access to further compromise the system or pivot to other internal resources.

Impact

Successful exploitation of CVE-2026-7042 allows an attacker to bypass authentication controls in MiroFish applications. This can lead to unauthorized access to sensitive data, modification of application settings, or complete system compromise. The lack of authentication on the REST API endpoint can have severe implications for data confidentiality, integrity, and availability. Given the availability of a public exploit, affected organizations are at immediate risk.

Recommendation

• Monitor web server logs for suspicious HTTP requests targeting the REST API Endpoint with unusual parameters, using the provided Sigma rule that detects anomalous HTTP methods in webserver logs.
• Apply any available patches or updates from 666ghj to address CVE-2026-7042 immediately.
• Review the affected backend/app/__init__.py file for authentication logic flaws and implement necessary security measures.