{"api_version":"1","generated_at":"2026-10-08T08:02:07+00:00","cve":"CVE-2026-103646","urls":{"html":"https://cve.report/CVE-2026-103646","api":"https://cve.report/api/cve/CVE-2026-103646.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-103646","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-103646"},"summary":{"title":"Ultimate Multisite < 2.17.0 - Unauthenticated Authentication Bypass via 'email_address' Parameter","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.","state":"PUBLISHED","assigner":"WPScan","published_at":"2026-10-08 06:16:37","updated_at":"2026-10-08 06:16:37"},"problem_types":["CWE-287 Improper Authentication"],"metrics":[],"references":[{"url":"https://wpscan.com/vulnerability/a05da0ad-5d92-406f-b182-b3ed1f8389f3/","name":"https://wpscan.com/vulnerability/a05da0ad-5d92-406f-b182-b3ed1f8389f3/","refsource":"contact@wpscan.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-103646","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-103646","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Unknown","product":"Ultimate Multisite","version":"affected 2.17.0 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Erwan LR (WPScan)","lang":"en"},{"source":"CNA","value":"WPScan","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Ultimate Multisite","vendor":"Unknown","versions":[{"lessThan":"2.17.0","status":"affected","version":"0","versionType":"semver"}]}],"credits":[{"lang":"en","type":"finder","value":"Erwan LR (WPScan)"},{"lang":"en","type":"coordinator","value":"WPScan"}],"descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"description":"CWE-287 Improper Authentication","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-08T06:00:05.353Z","orgId":"1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81","shortName":"WPScan"},"references":[{"tags":["exploit","vdb-entry","technical-description"],"url":"https://wpscan.com/vulnerability/a05da0ad-5d92-406f-b182-b3ed1f8389f3/"}],"source":{"discovery":"EXTERNAL"},"title":"Ultimate Multisite < 2.17.0 - Unauthenticated Authentication Bypass via 'email_address' Parameter","x_generator":{"engine":"WPScan CVE Generator"}}},"cveMetadata":{"assignerOrgId":"1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81","assignerShortName":"WPScan","cveId":"CVE-2026-103646","datePublished":"2026-10-08T06:00:05.353Z","dateReserved":"2026-10-01T06:42:15.491Z","dateUpdated":"2026-10-08T06:00:05.353Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-08 06:16:37","lastModifiedDate":"2026-10-08 06:16:37","problem_types":["CWE-287 Improper Authentication"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"103646","Ordinal":"1","Title":"Ultimate Multisite < 2.17.0 - Unauthenticated Authentication Byp","CVE":"CVE-2026-103646","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"103646","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Ultimate Multisite < 2.17.0 - Unauthenticated Authentication Byp"}]}}}