CVE-2025-13591
Username Enumeration via Authentication Endpoint in WSO2 Identity Server Allows User Account Discovery
Description
The authentication endpoint of WSO2 Identity Server fails to provide a consistent system response when a username does not exist in the system, allowing attackers to differentiate between valid and invalid usernames. This difference in responses can be leveraged to enumerate existing user accounts. Successful exploitation enables an attacker to discover valid usernames within the system, significantly increasing the risk of subsequent attacks such as brute force attacks on user credentials, social engineering attacks, and information leakage. The discovered usernames can be used to craft targeted phishing emails or other social engineering campaigns.
INFO
Published Date :
Oct. 19, 2026, 5:16 p.m.
Last Modified :
Oct. 19, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
ed10eef1-636d-4fbe-9993-6890dfa878f8
Affected Products
The following products are affected by CVE-2025-13591
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 3.1 | MEDIUM | ed10eef1-636d-4fbe-9993-6890dfa878f8 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Implement consistent error messages for all username lookups.
- Avoid revealing username existence in system responses.
- Apply security updates for WSO2 Identity Server.
- Review and harden authentication endpoint security.
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-2025-13591.
| URL | Resource |
|---|---|
| https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4583/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-13591 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-2025-13591
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-2025-13591 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-13591 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.
-
New CVE Received by ed10eef1-636d-4fbe-9993-6890dfa878f8
Oct. 19, 2026
Action Type Old Value New Value Added Description The authentication endpoint of WSO2 Identity Server fails to provide a consistent system response when a username does not exist in the system, allowing attackers to differentiate between valid and invalid usernames. This difference in responses can be leveraged to enumerate existing user accounts. Successful exploitation enables an attacker to discover valid usernames within the system, significantly increasing the risk of subsequent attacks such as brute force attacks on user credentials, social engineering attacks, and information leakage. The discovered usernames can be used to craft targeted phishing emails or other social engineering campaigns. Added CVSS V3.1 AV:N/AC:L/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-2025-13591.json">CVE-2025-13591</a> Added Reference https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4583/