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.

Project Subscriptions

Vendors Products
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Advisories

No advisories yet.

Fixes

Solution

Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4353/#solution


Workaround

No workaround given by the vendor.

History

Tue, 15 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Tue, 15 Sep 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Wso2
Wso2 wso2 Identity Server
Vendors & Products Wso2
Wso2 wso2 Identity Server

Tue, 15 Sep 2026 10:00:00 +0000

Type Values Removed Values Added
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.
Title Username Enumeration via SMS OTP Flow in WSO2 Identity Server 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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: WSO2

Published:

Updated: 2026-09-15T12:43:52.987Z

Reserved: 2025-11-14T06:00:52.219Z

Link: CVE-2025-13166

cve-icon Vulnrichment

Updated: 2026-09-15T12:43:39.447Z

cve-icon NVD

Status : Received

Published: 2026-09-15T10:17:00.877

Modified: 2026-09-15T13:16:38.937

Link: CVE-2025-13166

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T11:45:17Z

Weaknesses