{"id":"CVE-2026-109515","revision":null,"records":[{"revision":"ef00285d9b204d5b9d673c1c7e825093","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-109515","aliases":[],"title":"MailOptin <= 1.2.78.6 - Unauthenticated Privilege Escalation to 'form_custom_field_mappings' Parameter","description":"The MailOptin – Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc. plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.78.6 This is due to the `subscribe_to_email_list` endpoint accepting an attacker-supplied `optin_data[form_custom_field_mappings]` parameter without any allow-list validation on destination keys, allowing the attacker-controlled mapping to override the administrator's saved mapping and pass arbitrary `wp_users` column names — including `ID` and `user_pass` — directly into `wp_insert_user()` via the `subscribe()` function. This makes it possible for unauthenticated attackers to force `wp_insert_user()` into UPDATE mode on any existing account by supplying a target user's numeric `ID`, overwrite that account's password with a pre-hashed value of their choosing, and thereby take over any WordPress user account — including administrators — leading to full site compromise. Exploitation requires that a WordPress User Registration opt-in form is published somewhere on the site, though the form's UUID is visible in page source and no authentication, nonce, or capability check is required to reach the vulnerable endpoint.","state":0,"publishedAt":"2026-10-16T04:27:01.48+00:00","modifiedAt":"2026-10-16T15:09:39.848+00:00","affected":[{"ecosystem":"Vendor product","name":"MailOptin – Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc.","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"properfraction\",\n                    \"product\": \"MailOptin – Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc.\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"lessThanOrEqual\": \"1.2.78.6\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/96111116-6b6f-42fc-98d8-6f5c27dc3c1c?source=cve","https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/connections/WordPressUserRegistrationConnect/Subscription.php#L68","https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/Connections/AbstractConnect.php#L84","https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/AjaxHandler.php#L699","https://plugins.trac.wordpress.org/changeset?reponame=&new=3744644%40mailoptin%2Ftrunk&old=3738326%40mailoptin%2Ftrunk#file4","https://plugins.trac.wordpress.org/changeset/3744644/mailoptin/trunk/src/connections/WordPressUserRegistrationConnect/Subscription.php"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-109515","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-109515","identifiers":["CVE-2026-109515"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-994943cd8cb046f49f56409fe0b1d8c6","complete":false,"records":13655,"lastAttemptAt":"2026-11-09T10:16:43.0170247+00:00","lastSuccessAt":"2026-11-09T10:16:43.013+00:00","error":"6 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T10:16:43.013+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13701,"expectedIdentifiers":13707,"failedIdentifiers":6},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T10:04:34.0648037+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T10:04:34.0648037+00:00","lastSuccessAt":"2026-11-09T10:04:34.2253534+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:04:34.2253535+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-4dc74a26d06148ffa8eb6751d602315d","complete":true,"records":13667,"lastAttemptAt":"2026-11-09T10:04:35.2758607+00:00","lastSuccessAt":"2026-11-09T10:04:35.272+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:04:35.272+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13707,"expectedIdentifiers":13707,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T10:04:28.5294921+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:04:28.5294921+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T10:02:25.7473895+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:02:25.7473895+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-747b24005f13ffe3f133ae77dfb12ae3145f2c7aed5cfebb91eb943ceb4daeb6","complete":true,"records":3060,"lastAttemptAt":"2026-11-09T10:04:34.0336984+00:00","lastSuccessAt":"2026-11-09T10:04:33.8957851+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:04:34.0336984+00:00","snapshotPublishedAt":"2026-11-09T10:03:05+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-e6e6ac3eaece246ff08884368fe1dc99d4d393571e77c126c8f4d38d66697688","complete":true,"records":231297,"lastAttemptAt":"2026-11-09T10:04:28.3938244+00:00","lastSuccessAt":"2026-11-09T10:04:27.0059369+00:00","error":null,"lastVerifiedAt":"2026-11-09T10:04:28.3938244+00:00","snapshotPublishedAt":"2026-11-09T09:33:10+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}