Username Enumeration via Self Registration Flow in Multiple WSO2 Products Allows User Account Discovery

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.

Scores

EPSS (exploitation in 30 days)

0.33% · top 74% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.

Weakness

• CWE-203: Information Disclosure Through Error Messages (opens in a new tab)All about CWE-203 and its CVEs

Affected products

• WSO2 · WSO2 API Manager

  • unknown < 3.1.0
  • affected 3.1.0 – < 3.1.0.354
  • affected 3.2.0 – < 3.2.0.458
  • affected 3.2.0 – < 3.2.0.478
  • affected 3.2.1 – < 3.2.1.96
  • affected 4.0.0 – < 4.0.0.379
  • affected 4.1.0 – < 4.1.0.262
  • affected 4.2.0 – < 4.2.0.200
  • affected 4.3.0 – < 4.3.0.112
  • affected 4.4.0 – < 4.4.0.72
  • affected 4.5.0 – < 4.5.0.55
  • affected 4.6.0 – < 4.6.0.17

• WSO2 · WSO2 API Control Plane

  • unknown < 4.5.0
  • affected 4.5.0 – < 4.5.0.56
  • affected 4.6.0 – < 4.6.0.18

• WSO2 · WSO2 Universal Gateway

  • unknown < 4.5.0
  • affected 4.5.0 – < 4.5.0.55
  • affected 4.6.0 – < 4.6.0.17

• WSO2 · WSO2 Traffic Manager

  • unknown < 4.5.0
  • affected 4.5.0 – < 4.5.0.54
  • affected 4.6.0 – < 4.6.0.17

• WSO2 · WSO2 Identity Server

  • unknown < 5.10.0
  • affected 5.10.0 – < 5.10.0.383
  • affected 5.11.0 – < 5.11.0.430
  • affected 6.0.0 – < 6.0.0.257
  • affected 6.1.0 – < 6.1.0.234
  • affected 6.1.0 – < 6.1.0.257
  • affected 7.0.0 – < 7.0.0.133
  • affected 7.1.0 – < 7.1.0.41
  • affected 7.2.0 – < 7.2.0.3

• WSO2 · WSO2 Identity Server as Key Manager

  • unknown < 5.10.0
  • affected 5.10.0 – < 5.10.0.374

• WSO2 · WSO2 Open Banking AM

  • unknown < 2.0.0
  • affected 2.0.0 – < 2.0.0.403

• WSO2 · WSO2 Open Banking IAM

  • unknown < 2.0.0
  • affected 2.0.0 – < 2.0.0.423

• WSO2 · WSO2 Carbon Identity Management Endpoint Util

  • affected 5.17.5 – < 5.17.5.332
  • affected 5.18.187 – < 5.18.187.330
  • affected 5.23.8 – < 5.23.8.213
  • affected 5.25.92 – < 5.25.92.167
  • affected 7.0.78 – < 7.0.78.162
  • unaffected x – ≤ *

• WSO2 · WSO2 Carbon Identity Application Authentication Framework

  • affected 5.17.5 – < 5.17.5.332
  • affected 5.18.187 – < 5.18.187.330
  • unaffected x – ≤ *

What to do

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

References (1)

• https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4227/ (opens in a new tab)vendor-advisory

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2025-5802](https://trackcve.app/badge/CVE-2025-5802.svg)](https://trackcve.app/cve/CVE-2025-5802)

Record last updated 15 Sept 2026, 12:49 UTC.