{"id":"CVE-2026-103646","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-103646","generatedAt":"2026-10-23T21:16:55.611Z","title":"The Ultimate Multisite WordPress plugin before 2.17.0 does not require authentication before a logged-out checkout is linked to, and logged in as, an existing WordPress account matching the submitted email address, and its duplicate-account check…","description":"The Ultimate Multisite  WordPress plugin before 2.17.0 does not require authentication before a logged-out checkout is linked to, and logged in as, an existing WordPress account matching the submitted email address, and its duplicate-account check normalizes that address differently from the lookup used to create the customer, so an unauthenticated attacker can log in as any existing user, including a Network Super Admin, whose email address they know.\nThis bypass is not addressed by the 2.15.1 fix for CVE-2026-75957 and remains exploitable in all versions up to and including 2.16.1, the releases that fix was expected to cover. Exploitation requires a checkout form configured without a password field (auto-generated password) and a target account that has no existing customer record in the Ultimate Multisite  WordPress plugin before 2.17.0.","published":"2026-10-08T06:16:38.000Z","lastModified":"2026-10-08T20:51:18.000Z","status":"Deferred","sourceIdentifier":"contact@wpscan.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-287"],"affected":[],"epss":{"score":0.00442,"percentile":0.37412,"date":"2026-10-22","history":[{"date":"2026-10-08","score":0.00198,"percentile":0.08825}]},"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 (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-08T11:45:13.000Z","detail":{"from":null,"score":"9.8","severity":"CRITICAL","fromSeverity":null},"summary":"Now scored CVSS 9.8 CRITICAL."},{"kind":"new","label":"New CVE","at":"2026-10-08T06:16:38.000Z","detail":{"score":null,"severity":null,"publishedAt":"2026-10-08T06:16:37.957Z"},"summary":"New CVE, critical severity (CVSS 9.8)."}],"references":[{"url":"https://wpscan.com/vulnerability/a05da0ad-5d92-406f-b182-b3ed1f8389f3/","source":"contact@wpscan.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-103646","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."}