CVE-2025-13736 Username Enumeration via Login Interface in Multiple WSO2 Products Allows User Account Discovery

Low 3.7 Published 6 Aug 2026 Updated 6 Aug 2026

Attackers can enumerate valid usernames via the login interface when Multi-Attribute Login is enabled, facilitating targeted attacks.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-13736?

CVE-2025-13736 is a low-severity vulnerability in Wso2 Api Manager, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-203

Which versions are affected by CVE-2025-13736?

It affects 5 products.

Products include Wso2 Api Manager, Wso2 Identity Server, Wso2 Identity Server as Key Manager, Wso2 Open Banking Am, Wso2 Open Banking Iam.

How do I fix CVE-2025-13736?

No fix has been published for CVE-2025-13736 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-13736 being exploited?

There is no known exploitation of CVE-2025-13736 in the wild and no public exploit code.

All Wso2 Api Manager vulnerabilities

Sources

Also known as GHSA-g8w9-p6wx-8fxc.