{"id":"CVE-2025-5802","title":"The self-registration flow accepts user-supplied input for usernames without adequately preventing the disclosure of username existence","summary":"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 messag…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-203"],"vendor":"WSO2","product":"WSO2 API Manager","affected":["api_manager >= 3.1.0 < 3.1.0.354","api_manager >= 3.2.0 < 3.2.0.458","api_manager >= 3.2.0 < 3.2.0.478","api_manager >= 3.2.1 < 3.2.1.96","api_manager >= 4.0.0 < 4.0.0.379","api_manager >= 4.1.0 < 4.1.0.262","api_manager >= 4.2.0 < 4.2.0.200","api_manager >= 4.3.0 < 4.3.0.112","api_manager >= 4.4.0 < 4.4.0.72","api_manager >= 4.5.0 < 4.5.0.55","api_manager >= 4.6.0 < 4.6.0.17","api_control_plane >= 4.5.0 < 4.5.0.56","api_control_plane >= 4.6.0 < 4.6.0.18","universal_gateway >= 4.5.0 < 4.5.0.55","universal_gateway >= 4.6.0 < 4.6.0.17","traffic_manager >= 4.5.0 < 4.5.0.54","traffic_manager >= 4.6.0 < 4.6.0.17","identity_server >= 5.10.0 < 5.10.0.383","identity_server >= 5.11.0 < 5.11.0.430","identity_server >= 6.0.0 < 6.0.0.257","identity_server >= 6.1.0 < 6.1.0.234","identity_server >= 6.1.0 < 6.1.0.257","identity_server >= 7.0.0 < 7.0.0.133","identity_server >= 7.1.0 < 7.1.0.41","identity_server >= 7.2.0 < 7.2.0.3","identity_server_as_key_manager >= 5.10.0 < 5.10.0.374","open_banking_am >= 2.0.0 < 2.0.0.403","open_banking_iam >= 2.0.0 < 2.0.0.423","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.mgt.endpoint.util >= 5.17.5 < 5.17.5.332","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.mgt.endpoint.util >= 5.18.187 < 5.18.187.330","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.mgt.endpoint.util >= 5.23.8 < 5.23.8.213","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.mgt.endpoint.util >= 5.25.92 < 5.25.92.167","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.mgt.endpoint.util >= 7.0.78 < 7.0.78.162","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.application.authentication.framework >= 5.17.5 < 5.17.5.332","org.wso2.carbon.identity.framework:org.wso2.carbon.identity.application.authentication.framework >= 5.18.187 < 5.18.187.330"],"published":"2026-09-15","updated":"2026-09-18","sourceUpdated":"2026-09-18T19:13:15.430","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-5802","references":[{"url":"https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4227/","label":"ed10eef1-636d-4fbe-9993-6890dfa878f8"}],"tags":["nvd","cve.org"],"epss":0.00251,"epssPercentile":0.16771,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-15T12:48:59.851340Z"},"ingestedAt":"2026-09-15T10:35:28.511Z","slug":"CVE-2025-5802","body":"## Overview\n\nThe 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.\n\nThis 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}