{"id":"CVE-2018-3761","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-3761","generatedAt":"2026-10-28T19:05:14.042Z","title":"Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint.","description":"Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.","published":"2018-07-05T16:29:00.000Z","lastModified":"2026-06-17T01:57:47.000Z","status":"Modified","sourceIdentifier":"support@hackerone.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N"},"cwe":["CWE-287"],"affected":["nextcloud/nextcloud server"],"epss":{"score":0.01657,"percentile":0.76489,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.66%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://hackerone.com/reports/343111","tags":["Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://nextcloud.com/security/advisory/?id=nc-sa-2018-003","tags":["Broken Link","Vendor Advisory"],"source":"support@hackerone.com"},{"url":"https://hackerone.com/reports/343111","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://nextcloud.com/security/advisory/?id=nc-sa-2018-003","tags":["Broken Link","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-3761","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."}