CVE-2025-11750 identifies a security weakness in langgenius/dify-web version 1.6.0 related to its authentication error handling. The vulnerability stems from the application returning different error messages when a user attempts to log in or register with a non-existent username/email versus an existing username/email but incorrect password. Specifically, the system responds with "account not found" for non-existent accounts and a different message for incorrect passwords on existing accounts. This discrepancy violates best practices for standardized error handling (CWE-544), enabling attackers to perform user enumeration attacks by analyzing the error responses. User enumeration can be leveraged to identify valid accounts, which attackers may then target with social engineering, brute force, or credential stuffing attacks. The vulnerability does not directly expose passwords or allow unauthorized access but lowers the barrier for further attacks by confirming valid user identifiers. The CVSS 3.0 score of 4.3 reflects a medium severity, with attack vector being adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), low integrity impact (I:L), and no availability impact (A:N). There are no known exploits in the wild, and no patches have been linked yet. The issue highlights the importance of consistent error messaging in authentication flows to prevent information leakage.

For European organizations, this vulnerability primarily increases the risk of targeted attacks by enabling attackers to enumerate valid user accounts. This can lead to more effective phishing campaigns, social engineering, brute force attempts, and credential stuffing attacks, potentially resulting in unauthorized access if weak or reused passwords are present. While the vulnerability itself does not allow direct compromise of accounts or systems, it facilitates reconnaissance that can be leveraged in multi-stage attacks. Organizations in sectors with high-value user data or critical services—such as finance, healthcare, and government—may face increased risk from attackers exploiting this information leakage. Additionally, GDPR and other European data protection regulations emphasize minimizing personal data exposure, and user enumeration could be considered a data privacy concern. The vulnerability may also erode user trust if exploited, impacting reputation and compliance posture.

To mitigate CVE-2025-11750, organizations should implement standardized and generic error messages for authentication failures, ensuring that responses do not reveal whether a username or email exists. For example, use a uniform message such as "Invalid username or password" for all failed login attempts. Additionally, rate limiting and account lockout mechanisms should be enforced to reduce the risk of brute force and enumeration attacks. Multi-factor authentication (MFA) should be deployed to add an extra layer of security beyond passwords. Monitoring and alerting on suspicious login patterns can help detect enumeration attempts early. Developers should review authentication code to ensure compliance with CWE-544 guidelines and apply patches or updates from the vendor once available. Conducting regular security assessments and penetration tests focusing on authentication flows is also recommended. Finally, educating users about phishing and credential reuse risks can reduce the effectiveness of attacks facilitated by enumeration.