Vulnerability-Lookup

GHSA-F6HJ-W62G-R97P

Vulnerability from github – Published: 2026-10-16 06:30 – Updated: 2026-10-16 06:30

Details

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.

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-109515"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-16T05:17:29Z",
    "severity": "CRITICAL"
  },
  "details": "The MailOptin \u2013 Popup, Optin Forms \u0026 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\u0027s 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\u0027s numeric `ID`, overwrite that account\u0027s 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\u0027s UUID is visible in page source and no authentication, nonce, or capability check is required to reach the vulnerable endpoint.",
  "id": "GHSA-f6hj-w62g-r97p",
  "modified": "2026-10-16T06:30:26Z",
  "published": "2026-10-16T06:30:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109515"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/connections/WordPressUserRegistrationConnect/Subscription.php#L68"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/AjaxHandler.php#L699"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/mailoptin/tags/1.2.78.5/src/core/src/Connections/AbstractConnect.php#L84"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset/3744644/mailoptin/trunk/src/connections/WordPressUserRegistrationConnect/Subscription.php"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3744644%40mailoptin%2Ftrunk\u0026old=3738326%40mailoptin%2Ftrunk#file4"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/96111116-6b6f-42fc-98d8-6f5c27dc3c1c?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-109515 (GCVE-0-2026-109515)

Vulnerability from cvelistv5 – Published: 2026-10-16 04:27 – Updated: 2026-10-16 15:09

Title

MailOptin <= 1.2.78.6 - Unauthenticated Privilege Escalation to 'form_custom_field_mappings' Parameter

Summary

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.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 14:56 UTC

CWE

CWE-269 - Improper Privilege Management

Assigner

Wordfence CNA under the mitre root

CNA scorecard C 65/100 over 2287 records in the last 180 days details

References

6 references

URL	Tags
https://www.wordfence.com/threat-intel/vulnerabil…
https://plugins.trac.wordpress.org/browser/mailop…
https://plugins.trac.wordpress.org/browser/mailop…
https://plugins.trac.wordpress.org/browser/mailop…
https://plugins.trac.wordpress.org/changeset?repo…
https://plugins.trac.wordpress.org/changeset/3744…

Impacted products

1 product

Vendor	Product	Version
properfraction	MailOptin – Popup, Optin Forms & Email Newsletters for Mailchimp, HubSpot, AWeber Etc.	Affected: 0 , ≤ 1.2.78.6 (semver)

Credits

Kuba

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-109515",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T14:56:30.538755Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-16T15:09:39.848Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "MailOptin \u2013 Popup, Optin Forms \u0026 Email Newsletters for Mailchimp, HubSpot, AWeber Etc.",
          "vendor": "properfraction",
          "versions": [
            {
              "lessThanOrEqual": "1.2.78.6",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Kuba"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The MailOptin \u2013 Popup, Optin Forms \u0026 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\u0027s 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\u0027s numeric `ID`, overwrite that account\u0027s 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\u0027s UUID is visible in page source and no authentication, nonce, or capability check is required to reach the vulnerable endpoint."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-269",
              "description": "CWE-269 Improper Privilege Management",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-16T04:27:01.480Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "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=\u0026new=3744644%40mailoptin%2Ftrunk\u0026old=3738326%40mailoptin%2Ftrunk#file4"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset/3744644/mailoptin/trunk/src/connections/WordPressUserRegistrationConnect/Subscription.php"
        }
      ],
      "timeline": [
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          "lang": "en",
          "time": "2026-10-12T18:20:28.000Z",
          "value": "Vendor Notified"
        },
        {
          "lang": "en",
          "time": "2026-10-15T16:09:03.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "MailOptin \u003c= 1.2.78.6 - Unauthenticated Privilege Escalation to \u0027form_custom_field_mappings\u0027 Parameter"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
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    "datePublished": "2026-10-16T04:27:01.480Z",
    "dateReserved": "2026-10-12T18:05:34.654Z",
    "dateUpdated": "2026-10-16T15:09:39.848Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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