CVE-2025-13736

Username Enumeration via Login Interface in Multiple WSO2 Products Allows User Account Discovery

Published Aug 6, 2026 CVSS 3.1 · 3.7 Low EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4013/#solution

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Wso2 api Manager
Wso2 identity Server
Wso2 identity Server As Key Manager
Wso2 open Banking Am
Wso2 open Banking Iam
CPEs cpe:2.3:a:wso2:api_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:wso2:identity_server:*:*:*:*:*:*:*:*
cpe:2.3:a:wso2:identity_server_as_key_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:wso2:open_banking_am:*:*:*:*:*:*:*:*
cpe:2.3:a:wso2:open_banking_iam:*:*:*:*:*:*:*:*
Vendors & Products Wso2 api Manager
Wso2 identity Server
Wso2 identity Server As Key Manager
Wso2 open Banking Am
Wso2 open Banking Iam
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Wso2
Wso2 wso2 Api Manager
Wso2 wso2 Identity Server
Wso2 wso2 Identity Server As Key Manager
Wso2 wso2 Open Banking Am
Wso2 wso2 Open Banking Iam
Vendors & Products Wso2
Wso2 wso2 Api Manager
Wso2 wso2 Identity Server
Wso2 wso2 Identity Server As Key Manager
Wso2 wso2 Open Banking Am
Wso2 wso2 Open Banking Iam
Type Values Removed Values Added
Description 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.
Title Username Enumeration via Login Interface in Multiple WSO2 Products Allows User Account Discovery
Weaknesses CWE-203
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}