FreeScout, an open-source help desk and shared inbox application built on PHP's Laravel framework, suffers from a critical vulnerability identified as CVE-2026-27637. The issue lies in the TokenAuth middleware's method of generating authentication tokens. Tokens are created by computing an MD5 hash over a concatenation of the user_id, the created_at timestamp, and the application's APP_KEY. This approach results in predictable, static tokens that do not expire or rotate, violating best practices for secure token generation. The APP_KEY is a secret key used by Laravel applications, but it is frequently exposed due to misconfigurations or leaks, making it a common attack vector. If an attacker gains access to the APP_KEY, they can compute valid tokens for any user, including administrators, thereby bypassing password authentication entirely and achieving full account takeover. This vulnerability is classified under CWE-330 (Use of Insufficiently Random Values), highlighting the weakness in token randomness and unpredictability. The vulnerability can be exploited remotely without authentication or user interaction, increasing its risk. Although no active exploits have been reported, the high CVSS score (9.8) reflects the critical impact and ease of exploitation. The issue is fixed in FreeScout version 1.8.206, which updates the token generation mechanism to use secure, random values and proper token lifecycle management.

The impact of CVE-2026-27637 is severe for organizations using vulnerable versions of FreeScout. An attacker who obtains the APP_KEY can generate valid authentication tokens for any user, including administrators, enabling full account takeover without needing passwords or user interaction. This compromises confidentiality, integrity, and availability of the help desk system, allowing unauthorized access to sensitive customer support data, internal communications, and potentially other integrated systems. Attackers could manipulate tickets, escalate privileges, exfiltrate data, or disrupt support operations. Since FreeScout is often used by organizations to manage customer inquiries and internal workflows, compromise could lead to data breaches, reputational damage, and operational downtime. The static nature of tokens exacerbates the risk, as tokens do not expire or rotate, allowing persistent unauthorized access once compromised. The vulnerability's remote exploitability and lack of required authentication make it attractive for attackers. Organizations relying on FreeScout in sectors such as IT services, customer support, and SMBs are particularly at risk.

To mitigate CVE-2026-27637, organizations should immediately upgrade FreeScout to version 1.8.206 or later, where the vulnerability is patched. If upgrading is not immediately possible, administrators should rotate the Laravel APP_KEY to invalidate any previously generated tokens and prevent attackers from computing valid tokens. It is critical to audit and secure the APP_KEY storage and access controls to prevent leakage, including restricting file permissions and environment variable exposure. Additionally, implement monitoring and alerting for suspicious authentication token usage or unexpected administrative access. Consider enforcing multi-factor authentication (MFA) on administrative accounts to add an additional security layer. Review and harden Laravel application configurations to prevent APP_KEY exposure, such as securing deployment pipelines and environment files. Finally, conduct a thorough security assessment of the FreeScout deployment and related infrastructure to identify and remediate any other potential vulnerabilities or misconfigurations.