CVE-2025-13736Network attack vector

Account discovery via inconsistent username normalization

Published Aug 6, 2026 · Updated Aug 6, 2026

Username enumeration in multiple WSO2 server products allows remote attackers to discover valid accounts through the login interface. With Multi-Attribute Login enabled, the interface replaces valid aliases with their canonical usernames but echoes nonexistent inputs, creating an observable response discrepancy regardless of validate_username. No authentication is required, and the disclosed account names support targeted password guessing, phishing, and social engineering without granting account access.

CVSS severity3.7
Low
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Username enumeration in multiple WSO2 server products allows remote attackers to discover valid accounts through the login interface. With Multi-Attribute Login enabled, the interface replaces valid aliases with their canonical usernames but echoes nonexistent inputs, creating an observable response discrepancy regardless of validate_username. No authentication is required, and the disclosed account names support targeted password guessing, phishing, and social engineering without granting account access.

The record

CVE
CVE-2025-13736
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
WSO2
Product
WSO2 Identity Server
Classifications
CWE-203, CAPEC-24, T1589.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.10.0 <5.10.0.380
  2. Affected versionversion=5.11.0 <5.11.0.427
  3. Affected versionversion=6.0.0 <6.0.0.254
  4. Affected versionversion=6.1.0 <6.1.0.255
  5. Affected versionversion=7.0.0 <7.0.0.132
  6. Affected versionversion=7.1.0 <7.1.0.40
  7. Affected versionversion=7.2.0 <7.2.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WSO2 · WSO2 Identity Serverversion=5.10.0 <5.10.0.380; version=5.11.0 <5.11.0.427; version=6.0.0 <6.0.0.254; version=6.1.0 <6.1.0.255; version=7.0.0 <7.0.0.132; version=7.1.0 <7.1.0.40; version=7.2.0 <7.2.0.2
WSO2 · WSO2 Open Banking AMversion=2.0.0 <2.0.0.400
WSO2 · WSO2 Open Banking IAMversion=2.0.0 <2.0.0.420
WSO2 · WSO2 Identity Server as Key Managerversion=5.10.0 <5.10.0.371
WSO2 · WSO2 API Managerversion=3.1.0 <3.1.0.351; version=3.2.0 <3.2.0.455; version=4.0.0 <4.0.0.375

Published CVSS scores

3.7WSO2CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy
CAPEC-24Username Enumeration
T1589.003Gather Victim Identity Information: Employee Names

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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