The vulnerability identified as CVE-2025-62425 affects the matrix-authentication-service (MAS), a component developed by Element for managing user authentication on Matrix homeservers. MAS versions from 0.20.0 up to and including 1.4.0 contain a logic flaw classified under CWE-620 (Unverified Password Change). This flaw permits an attacker who already has an authenticated session on MAS to perform sensitive account operations—such as changing the account password, adding or removing email addresses, and deactivating the account—without needing to provide the current password. The vulnerability is specifically present when the local password database feature is enabled in the MAS configuration. The attack vector requires network access (remote) and low attack complexity, with privileges required being limited to an authenticated session, and no user interaction needed. The vulnerability impacts confidentiality (unauthorized access to account credentials), integrity (unauthorized changes to account details), and availability (account deactivation). The flaw was addressed and patched in version 1.4.1 of MAS. No known exploits are currently reported in the wild, but the high CVSS score (8.3) reflects the potential severity if exploited. This vulnerability poses a significant risk to organizations relying on Matrix homeservers for secure communications, especially where local password management is enabled.

For European organizations, the impact of CVE-2025-62425 can be substantial. Matrix is increasingly adopted in privacy-conscious sectors, including government, healthcare, and enterprises, for secure real-time communication. Exploitation could lead to unauthorized account takeovers, allowing attackers to intercept or manipulate sensitive communications, potentially violating GDPR and other data protection regulations. The ability to deactivate accounts could disrupt business operations and cause denial of service to legitimate users. The integrity of user identity management is compromised, undermining trust in the authentication system. Organizations with local password databases enabled are at direct risk, and the breach could cascade to other connected systems relying on Matrix authentication. The lack of required user interaction and the remote attack vector increase the likelihood of exploitation in targeted attacks or insider threat scenarios.

European organizations should immediately verify if their MAS deployments use the local password database feature and identify affected versions (0.20.0 to 1.4.0). The primary mitigation is to upgrade MAS to version 1.4.1 or later, where the vulnerability is patched. Until the upgrade is applied, organizations should enforce strict session management policies, including short session timeouts and monitoring for anomalous account changes. Implement multi-factor authentication (MFA) at the Matrix homeserver level to reduce the risk of session compromise. Audit logs should be reviewed for unauthorized password changes, email modifications, or account deactivations. Network segmentation and access controls should limit MAS access to trusted internal networks or VPNs. Additionally, organizations should educate users about the importance of session security and consider deploying intrusion detection systems tuned to detect suspicious MAS activity. Regular vulnerability scanning and penetration testing focused on authentication services are recommended to detect similar logic flaws proactively.