What’s Vulnerable › Vulnerabilities
CVE-2025-13166: Username Enumeration via SMS OTP Flow in WSO2 Identity Server Allows User Account Discovery
- Severity: low (CVSS 3.7 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-15 · updated 2026-10-14
- Weakness: CWE-203
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
- WSO2 Identity Server: from 7.1.0 before 7.1.0.40; from 7.2.0 before 7.2.0.2 — fixed in 7.1.0.40, 7.2.0.2
How to fix
Upgrade to a fixed version: WSO2 Identity Server 7.1.0.40, 7.2.0.2. Check the vendor advisory for mitigations.
References
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