CVE-2026-109515

{"id": "CVE-2026-109515", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-109515", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T14:56:30.538755Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@wordfence.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@wordfence.com", "affectedData": [{"vendor": "properfraction", "product": "MailOptin \u2013 Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc.", "versions": [{"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "1.2.78.6"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-16T05:17:29.597", "references": [{"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/connections/WordPressUserRegistrationConnect/Subscription.php#L68", "source": "security@wordfence.com"}, {"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/AjaxHandler.php#L699", "source": "security@wordfence.com"}, {"url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/Connections/AbstractConnect.php#L84", "source": "security@wordfence.com"}, {"url": "https://plugins.trac.wordpress.org/changeset/3744644/mailoptin/trunk/src/connections/WordPressUserRegistrationConnect/Subscription.php", "source": "security@wordfence.com"}, {"url": "https://plugins.trac.wordpress.org/changeset?reponame=&new=3744644%40mailoptin%2Ftrunk&old=3738326%40mailoptin%2Ftrunk#file4", "source": "security@wordfence.com"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/96111116-6b6f-42fc-98d8-6f5c27dc3c1c?source=cve", "source": "security@wordfence.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security@wordfence.com", "description": [{"lang": "en", "value": "CWE-269"}]}], "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."}], "lastModified": "2026-10-16T15:17:07.900", "sourceIdentifier": "security@wordfence.com"}