CVE-2025-5802
CVE-2025-5802 — Username Enumeration via Self Registration Flow in Multiple WSO2 Products Allows User Account Discovery
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.
Published Updated Sources: NVD, WSO2 (CNA), GitHub, SOCRadar CTI
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Exploit code
public exploit, none observed
EPSS
0%
ahead of 0% of scored CVEs
CVSS base
5.3
medium
Remediation
The vendor's own words where we have them.
Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4227/#solution
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Prioritize based on EPSS, PoC availability, and external exposure.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| WSO2 | WSO2 API Manager | 0 to < 3.1.0 | Vulnerable |
| WSO2 | WSO2 API Manager | 3.1.0 to < 3.1.0.354 | Vulnerable |
| WSO2 | WSO2 API Manager | 3.2.0 to < 3.2.0.458 | Vulnerable |
| WSO2 | WSO2 API Manager | 3.2.0 to < 3.2.0.478 | Vulnerable |
| WSO2 | WSO2 API Manager | 3.2.1 to < 3.2.1.96 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.0.0 to < 4.0.0.379 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.1.0 to < 4.1.0.262 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.2.0 to < 4.2.0.200 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.3.0 to < 4.3.0.112 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.4.0 to < 4.4.0.72 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.5.0 to < 4.5.0.55 | Vulnerable |
| WSO2 | WSO2 API Manager | 4.6.0 to < 4.6.0.17 | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
None
Confidentiality
Low
Integrity
None
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 5.3 | CVSS 3.1 | medium | 3.9 | 1.4 | CNA, WSO2 (CNA) |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
What this weakness leads to
MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.
CWE-203 · Observable Discrepancy
- Read Application Data
- Bypass Protection Mechanism
Mitigation: Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Weakness & attack patterns
- CWE-203
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
4
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable WSO2 API Manager, WSO2 API Control Plane, WSO2 Universal Gateway, WSO2 Traffic Manager, WSO2 Identity Server, WSO2 Identity Server as Key Manager, WSO2 Open Banking AM, WSO2 Open Banking IAM, WSO2 Carbon Identity Management Endpoint Util, WSO2 Carbon Identity Application Authentication Framework.
- Monitor for scanner or exploit-pattern traffic after 4 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 5.3 (AV:N)
Sep 15, 2026 · NVD
Initial · CVE published
Sep 15, 2026 · NVD
CVE published by MITRE.
Sep 15, 2026 · SOCRadar CTI
References
1 on the record
Elsewhere on this site
- WSO2every CVE for this vendor
- Unclassifiedsame class
- CWE-203other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2025-5802 is Username Enumeration via Self Registration Flow in Multiple WSO2 Products Allows User Account Discovery, a medium vulnerability affecting WSO2 API Manager, WSO2 API Control Plane, WSO2 Universal Gateway, WSO2 Traffic Manager, WSO2 Identity Server, WSO2 Identity Server as Key Manager, WSO2 Open Banking AM, WSO2 Open Banking IAM, WSO2 Carbon Identity Management Endpoint Util, WSO2 Carbon Identity Application Authentication Framework from WSO2. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2025-5802. Public exploit evidence is: 4 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.3 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.