The self-registration flow accepts user-supplied input for usernames without adequately preventing the disclosure of username existence. When a user attempts to register with an existing username, the system responds with an error message that explicitly indicates the username is already in use.

This behavior allows an attacker to discover valid usernames within the system. The discovery of valid usernames can facilitate subsequent attacks such as brute force, social engineering, and targeted phishing campaigns.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.0033.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

No data.

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4227/#solution

Workaround

No workaround given by the vendor.

References
Link Providers
https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4227/ cve-icon cve-icon
History

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

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

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

Type Values Removed Values Added
Description The self-registration flow accepts user-supplied input for usernames without adequately preventing the disclosure of username existence. When a user attempts to register with an existing username, the system responds with an error message that explicitly indicates the username is already in use. This behavior allows an attacker to discover valid usernames within the system. The discovery of valid usernames can facilitate subsequent attacks such as brute force, social engineering, and targeted phishing campaigns.
Title Username Enumeration via Self Registration Flow in Multiple WSO2 Products Allows User Account Discovery
Weaknesses CWE-203
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/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: 2026-09-15T12:49:19.401Z

Reserved: 2025-06-06T09:33:38.579Z

Link: CVE-2025-5802

cve-icon Vulnrichment

Updated: 2026-09-15T12:49:16.517Z

cve-icon NVD

Status : Received

Published: 2026-09-15T10:17:02.640

Modified: 2026-09-15T13:16:40.277

Link: CVE-2025-5802

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses