CVE-2025-13166
Username Enumeration via SMS OTP Flow in WSO2 Identity Server Allows User Account Discovery
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.
INFO
Published Date :
Sept. 15, 2026, 10:17 a.m.
Last Modified :
Sept. 15, 2026, 11:17 p.m.
Remotely Exploit :
Yes !
Source :
ed10eef1-636d-4fbe-9993-6890dfa878f8
Affected Products
The following products are affected by CVE-2025-13166
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | ed10eef1-636d-4fbe-9993-6890dfa878f8 |
Solution
- Modify error messages to be generic and non-revealing.
- Implement rate limiting for OTP initiation requests.
- Sanitize responses to obscure account existence information.
- Log enumeration attempts for security monitoring.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-13166.
| URL | Resource |
|---|---|
| https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4353/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-13166 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-13166
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-13166 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-13166 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by ed10eef1-636d-4fbe-9993-6890dfa878f8
Sep. 15, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/13xxx/CVE-2025-13166.json">CVE-2025-13166</a> -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 15, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2025-13166', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-15T12:43:12.334732Z'} -
New CVE Received by ed10eef1-636d-4fbe-9993-6890dfa878f8
Sep. 15, 2026
Action Type Old Value New Value 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-203 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/13xxx/CVE-2025-13166.json">CVE-2025-13166</a> Added Reference https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4353/