Vulnerability · Published Sep 15, 2026 · Assigned by WSO2
CVE-2025-13166Username Enumeration via SMS OTP Flow in WSO2 Identity Server Allows User Account Discovery
Low 3.7
In plain English
A low-severity security flaw in WSO2 Identity Server from WSO2. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities).
Official description
The SMS OTP flow fails to adequately handle error messages, allowing an attacker to infer the existence of registered user accounts based on the responses received during the OTP initiation process. This weakness can be exploited by an attacker to discover valid usernames within the system. The impact is amplified for accounts that have not configured a mobile number, as the enumeration is specifically tied to this condition. The discovery of these usernames can facilitate subsequent brute force attacks, social engineering attempts, and information leakage, potentially leading to reputational damage, loss of customer trust, and regulatory non-compliance.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WSO2 | WSO2 Identity Server | 7.1.0 – before 7.1.0.407.2.0 – before 7.2.0.2 |
Weakness: CWE-203 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N