CVE-2025-13736: WSO2 API Manager

Low severity, CVSS 3.7. EPSS: 0.3% chance of exploitation in the next 30 days.

When Multi-Attribute Login is enabled, the login interface fails to consistently mask the existence of user accounts. For valid users, the server resolves and displays their canonical username, while for non-existent users, it echoes the original input. This occurs regardless of the validate_username configuration. The discovery of valid usernames can increase the risk of brute force attacks, social engineering attacks, and targeted information leakage. Attackers can leverage this information to craft more effective phishing campaigns or social engineering tactics to compromise user accounts or extract sensitive data.

Affected products

• WSO2 API Manager: from 3.1.0, before 3.1.0.351 (fixed in 3.1.0.351); from 3.2.0, before 3.2.0.455 (fixed in 3.2.0.455); from 4.0.0, before 4.0.0.375 (fixed in 4.0.0.375)
• WSO2 Identity Server: from 5.10.0, before 5.10.0.380 (fixed in 5.10.0.380); from 5.11.0, before 5.11.0.427 (fixed in 5.11.0.427); from 6.0.0, before 6.0.0.254 (fixed in 6.0.0.254); from 6.1.0, before 6.1.0.255 (fixed in 6.1.0.255); from 7.0.0, before 7.0.0.132 (fixed in 7.0.0.132); from 7.1.0, before 7.1.0.40 (fixed in 7.1.0.40); …
• WSO2 Identity Server As Key Manager: from 5.10.0, before 5.10.0.371 (fixed in 5.10.0.371)
• WSO2 Open Banking AM: from 2.0.0, before 2.0.0.400 (fixed in 2.0.0.400)
• WSO2 Open Banking Iam: from 2.0.0, before 2.0.0.420 (fixed in 2.0.0.420)

Published 2026-08-06. Last modified 2026-09-29.