{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-109515", "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "state": "PUBLISHED", "assignerShortName": "Wordfence", "dateReserved": "2026-10-12T18:05:34.654Z", "datePublished": "2026-10-16T04:27:01.480Z", "dateUpdated": "2026-10-16T04:27:01.480Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "shortName": "Wordfence", "dateUpdated": "2026-10-16T04:27:01.480Z"}, "affected": [{"vendor": "properfraction", "product": "MailOptin \u2013 Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc.", "versions": [{"version": "0", "status": "affected", "lessThanOrEqual": "1.2.78.6", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "The MailOptin \u2013 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 \u2014 including `ID` and `user_pass` \u2014 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 \u2014 including administrators \u2014 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."}], "title": "MailOptin <= 1.2.78.6 - Unauthenticated Privilege Escalation to 'form_custom_field_mappings' Parameter", "references": [{"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/96111116-6b6f-42fc-98d8-6f5c27dc3c1c?source=cve"}, {"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/connections/WordPressUserRegistrationConnect/Subscription.php#L68"}, {"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/Connections/AbstractConnect.php#L84"}, {"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/AjaxHandler.php#L699"}, {"url": "https://plugins.trac.wordpress.org/changeset?reponame=&new=3744644%40mailoptin%2Ftrunk&old=3738326%40mailoptin%2Ftrunk#file4"}, {"url": "https://plugins.trac.wordpress.org/changeset/3744644/mailoptin/trunk/src/connections/WordPressUserRegistrationConnect/Subscription.php"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-269 Improper Privilege Management", "cweId": "CWE-269", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}}], "credits": [{"lang": "en", "type": "finder", "value": "Kuba"}], "timeline": [{"time": "2026-10-12T18:20:28.000Z", "lang": "en", "value": "Vendor Notified"}, {"time": "2026-10-15T16:09:03.000Z", "lang": "en", "value": "Disclosed"}]}}}

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