{"id":"CVE-2025-13591","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-13591","generatedAt":"2026-10-28T04:15:13.305Z","title":"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.","description":"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.\n\nSuccessful 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.","published":"2026-10-19T17:16:59.000Z","lastModified":"2026-10-20T20:17:11.000Z","status":"Awaiting Analysis","sourceIdentifier":"ed10eef1-636d-4fbe-9993-6890dfa878f8","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-203"],"affected":[],"epss":{"score":0.00297,"percentile":0.22247,"date":"2026-10-27","history":[{"date":"2026-10-20","score":0.00225,"percentile":0.12388}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-19T17:16:59.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-10-19T17:16:59.413Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4583/","source":"ed10eef1-636d-4fbe-9993-6890dfa878f8"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-13591","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}