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TI-2025-43933 Aliases CVE-2025-13591GHSA-9j2j-6wwh-jwf6

Username enumeration via authentication endpoint in WSO2 Identity Server

Priority LOW 24CWE-203Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-203.

Summary

WSO2 Identity Server from 7.0.0 before 7.0.0.134 and from 7.1.0 before 7.1.0.42 is affected, along with WSO2 Carbon Abstract OTP Authenticator and Email OTP Authenticator. The authentication endpoint returns responses that differ depending on whether a username exists, which is an observable discrepancy (CWE-203). A remote attacker without authentication can tell valid usernames from invalid ones and enumerate existing user accounts. The discovered usernames can support brute force attempts, social engineering and targeted phishing.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00297 22nd percentileScored 2026-11-07
Fix Fixed WSO2 Identity Server (WSO2): 7.0.0.134, 7.1.0.42WSO2 Carbon Abstract OTP Authenticator (WSO2): 1.0.5.3, 1.0.10.2+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
WSO2WSO2 Identity Server7.0.0 to before 7.0.0.134; 7.1.0 to before 7.1.0.427.0.0.134, 7.1.0.42Patch availableCNA
WSO2WSO2 Carbon Abstract OTP Authenticator1.0.5 to before 1.0.5.3; 1.0.10 to before 1.0.10.21.0.5.3, 1.0.10.2Patch availableCNA
WSO2Email OTP Authenticator1.0.18 to before 1.0.18.8; 1.0.30 to before 1.0.30.51.0.18.8, 1.0.30.5Patch availableCNA
  • WSO2 Identity Server VendorWSO2 Affected 7.0.0 to before 7.0.0.134; 7.1.0 to before 7.1.0.42 Fixed in 7.0.0.134, 7.1.0.42 Patch available CNA
  • WSO2 Carbon Abstract OTP Authenticator VendorWSO2 Affected 1.0.5 to before 1.0.5.3; 1.0.10 to before 1.0.10.2 Fixed in 1.0.5.3, 1.0.10.2 Patch available CNA
  • Email OTP Authenticator VendorWSO2 Affected 1.0.18 to before 1.0.18.8; 1.0.30 to before 1.0.30.5 Fixed in 1.0.18.8, 1.0.30.5 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:wso2:identity_server:*:*:*:*:*:*:*:*——WSO2
  • cpe:2.3:a:wso2:identity_server:*:*:*:*:*:*:*:* Versions — — ·WSO2

Remediation

Upgrade WSO2 Identity Server to 7.0.0.134 or 7.1.0.42, WSO2 Carbon Abstract OTP Authenticator to 1.0.5.3 or 1.0.10.2, and Email OTP Authenticator to 1.0.18.8 or 1.0.30.5.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA WSO2 Identity Server (WSO2) Fixed in 7.0.0.134, 7.1.0.42
  • Fix · CNA WSO2 Carbon Abstract OTP Authenticator (WSO2) Fixed in 1.0.5.3, 1.0.10.2
  • Fix · CNA Email OTP Authenticator (WSO2) Fixed in 1.0.18.8, 1.0.30.5

Timeline

  1. 2026-10-19 Threatist record created from CVE-2025-13591
  2. 2026-10-20 Alias added: GHSA-9j2j-6wwh-jwf6
  3. 2026-10-20 CISA SSVC decision points changed

References

Advisory 1

  • TI-2026-04755 Authentication Bypass via JWT Algorithm Mismatch in Multiple WSO2 Products Allows Account Takeover KEVCVSS 3.1CRITICAL 10.0
  • TI-2022-11928 Certain WSO2 products allow unrestricted file upload with resultant remote code execution. KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-18808 An issue was discovered in WSO2 Enterprise Integrator 6.4.0. CVSS 3.1MEDIUM 6.1
  • TI-2020-15069 The Management Console in WSO2 API Manager through 3.1.0 and API Microgateway 2.2.0… CVSS 3.1CRITICAL 9.1
  • TI-2023-15163 A reflected cross-site scripting (XSS) vulnerability in /authenticationendpoint/login.do… CVSS 3.1MEDIUM 6.1
  • TI-2022-04130 WSO2 carbon-registry Advanced Search advancedSearchForm-ajaxprocessor.jsp cross site scripting CVSS 3.1MEDIUM 6.1
See all 186 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences