Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.25% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2025-5802High confidence
Username Enumeration via Self Registration Flow in Multiple WSO2 Products Allows User Account Discovery
WSO2 · WSO2 API Manager
5.3MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs WSO2 WSO2 API Manager and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
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.
What
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.
Why
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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.
Why
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Observable Discrepancy → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-203 ↗
CWE-203: Observable Discrepancy. The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- WSO2 Universal Gateway: 4.6.0 < 4.6.0.17, 4.5.0 < 4.5.0.55
- WSO2 API Control Plane: 4.5.0 < 4.5.0.56, 4.6.0 < 4.6.0.18
- WSO2 Identity Server: 6.1.0 < 6.1.0.257, 7.0.0 < 7.0.0.133, 5.11.0 < 5.11.0.430, 6.0.0 < 6.0.0.257, 5.10.0 < 5.10.0.383, 6.1.0 < 6.1.0.234, 7.2.0 < 7.2.0.3, 7.1.0 < 7.1.0.41
- WSO2 Carbon Identity Application Authentication Framework: 5.17.5 < 5.17.5.332, 5.18.187 < 5.18.187.330
- WSO2 Carbon Identity Management Endpoint Util: 5.23.8 < 5.23.8.213, 5.18.187 < 5.18.187.330, 5.17.5 < 5.17.5.332, 7.0.78 < 7.0.78.162, 5.25.92 < 5.25.92.167
- WSO2 API Manager: 3.2.0 < 3.2.0.458, 4.4.0 < 4.4.0.72, 3.2.0 < 3.2.0.478, 4.2.0 < 4.2.0.200, 4.5.0 < 4.5.0.55, 4.6.0 < 4.6.0.17, 4.3.0 < 4.3.0.112, 3.2.1 < 3.2.1.96, 4.0.0 < 4.0.0.379, 3.1.0 < 3.1.0.354, 4.1.0 < 4.1.0.262
- WSO2 Open Banking AM: 2.0.0 < 2.0.0.403
- WSO2 Open Banking IAM: 2.0.0 < 2.0.0.423
- WSO2 Identity Server as Key Manager: 5.10.0 < 5.10.0.374
- WSO2 Traffic Manager: 4.5.0 < 4.5.0.54, 4.6.0 < 4.6.0.17
- Fixed
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 15 Sept 2026 · Last source change 15 Sept 2026, 12:49 UTC · CWE-203 · Observable Discrepancy
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-15
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-210910
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2025-210910 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2025-210910"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.