CVE-2026-28571 in FormyChat Plugin
Summary
by MITRE • 08/18/2026
Unauthenticated Broken Access Control in FormyChat <= 2.15.7 versions.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified as an unbroken access control issue within FormyChat versions up to and including 2.15.7 represents a critical failure in the application's authorization logic, allowing attackers to perform actions without proper authentication or with insufficient privileges. This class of flaw is fundamentally rooted in the server-side enforcement mechanisms failing to verify user permissions before processing requests that modify state or expose sensitive data. In modern web applications and chat platforms, access control decisions must be enforced consistently at every layer of the architecture, particularly on the backend API endpoints that handle message delivery, user management, and configuration changes. When these checks are missing or bypassed, it creates a direct pathway for unauthorized entities to interact with the system as if they were legitimate users or administrators.
From a technical perspective, this vulnerability likely manifests through improper validation of session tokens, role-based access control (RBAC) misconfigurations, or insecure direct object references in API endpoints. An attacker can exploit these weaknesses by crafting specific HTTP requests that target internal functions intended for authenticated sessions only. For instance, the application may fail to check if the requesting user has the requisite administrative rights before executing a command such as deleting messages, changing system settings, or accessing other users' private conversations. This lack of server-side validation allows remote attackers to manipulate the state of the chat platform without needing valid credentials for high-privilege accounts, effectively bypassing the intended security boundaries established by the developers.
The operational impact of this vulnerability is severe, as it compromises the core principles of confidentiality, integrity, and availability that underpin secure communication platforms. Attackers can leverage this flaw to exfiltrate sensitive private messages, leading to significant data breaches and privacy violations for all users on the affected instance. Furthermore, the ability to modify system configurations or delete content undermines the integrity of the platform, potentially causing service disruption or reputational damage. In enterprise environments where FormyChat might be deployed for internal communications, such a breach could expose proprietary information, strategic plans, or personal employee data to competitors or malicious actors. The unauthenticated nature of the exploit means that no prior compromise is necessary, increasing the likelihood of automated scanning and exploitation by threat actors targeting vulnerable instances across the internet.
This vulnerability aligns with Common Weakness Enumeration (CWE) ID 284, which describes Improper Access Control, specifically highlighting failures in authorization checks. It also maps to several techniques within the MITRE ATT&CK framework, including T1078 Valid Accounts if the attacker escalates privileges after initial access, and more critically T1530 Data from Cloud Storage or T1046 Network Service Discovery depending on how the data is exfiltrated. The lack of authentication for sensitive operations falls squarely under unauthorized resource consumption and privilege escalation vectors that are frequently exploited in web application attacks.
To mitigate this risk, immediate action must be taken to upgrade FormyChat to a version greater than 2.15.7 where these access control flaws have been addressed by the vendor. In addition to upgrading, organizations should implement robust input validation and enforce strict server-side authorization checks on all API endpoints, ensuring that every request is verified against the user's current session permissions before execution. Deploying a Web Application Firewall (WAF) with rules tailored to detect abnormal access patterns can provide an additional layer of defense by blocking requests that attempt to bypass authentication mechanisms. Regular security audits and penetration testing should also be conducted to identify similar logic flaws in other parts of the application, ensuring comprehensive protection against broken access control vulnerabilities.