Vulnerability-Lookup

GHSA-VR4H-G9WJ-2P4G

Vulnerability from github – Published: 2026-05-29 09:31 – Updated: 2026-05-29 09:31

Details

The Contact Form 7 – PayPal & Stripe Add-on plugin for WordPress is vulnerable to Payment Bypass via Insufficient Verification of Data Authenticity in all versions up to, and including, 2.4.9. Although cf7pp_paypal_ipn_handler() correctly validates IPN authenticity by posting back to PayPal with cmd=_notify-validate, it fails to compare the IPN payload's mc_gross (payment amount), mc_currency, or receiver_email fields against the corresponding stored order values before passing the attacker-controlled invoice field directly to cf7pp_complete_payment(), which marks the order completed after only an integer cast with no amount verification. This makes it possible for unauthenticated attackers to mark arbitrary high-value pending orders as fully paid by making a minimal real PayPal payment and crafting an IPN whose invoice parameter references the targeted order, effectively completing purchases without tendering the required payment amount.

Severity

5.3 (Medium)


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

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-9189"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-345"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-29T09:16:18Z",
    "severity": "MODERATE"
  },
  "details": "The Contact Form 7 \u2013 PayPal \u0026 Stripe Add-on plugin for WordPress is vulnerable to Payment Bypass via Insufficient Verification of Data Authenticity in all versions up to, and including, 2.4.9. Although `cf7pp_paypal_ipn_handler()` correctly validates IPN authenticity by posting back to PayPal with `cmd=_notify-validate`, it fails to compare the IPN payload\u0027s `mc_gross` (payment amount), `mc_currency`, or `receiver_email` fields against the corresponding stored order values before passing the attacker-controlled `invoice` field directly to `cf7pp_complete_payment()`, which marks the order completed after only an integer cast with no amount verification. This makes it possible for unauthenticated attackers to mark arbitrary high-value pending orders as fully paid by making a minimal real PayPal payment and crafting an IPN whose `invoice` parameter references the targeted order, effectively completing purchases without tendering the required payment amount.",
  "id": "GHSA-vr4h-g9wj-2p4g",
  "modified": "2026-05-29T09:31:07Z",
  "published": "2026-05-29T09:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9189"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/functions.php#L31"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/paypal_handler.php#L106"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/paypal_handler.php#L75"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/functions.php#L31"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/paypal_handler.php#L106"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/paypal_handler.php#L75"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset/3551197/contact-form-7-paypal-add-on"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5e274781-1c20-4224-bc10-26dadb9b1e07?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-9189 (GCVE-0-2026-9189)

Vulnerability from cvelistv5 – Published: 2026-05-29 08:28 – Updated: 2026-05-29 10:04

Title

Contact Form 7 – PayPal & Stripe Add-on <= 2.4.9 - Unauthenticated Payment Bypass via Insufficient Verification of Data Authenticity via PayPal IPN Handler ('invoice'/'mc_gross' Verification)

Summary

The Contact Form 7 – PayPal & Stripe Add-on plugin for WordPress is vulnerable to Payment Bypass via Insufficient Verification of Data Authenticity in all versions up to, and including, 2.4.9. Although `cf7pp_paypal_ipn_handler()` correctly validates IPN authenticity by posting back to PayPal with `cmd=_notify-validate`, it fails to compare the IPN payload's `mc_gross` (payment amount), `mc_currency`, or `receiver_email` fields against the corresponding stored order values before passing the attacker-controlled `invoice` field directly to `cf7pp_complete_payment()`, which marks the order completed after only an integer cast with no amount verification. This makes it possible for unauthenticated attackers to mark arbitrary high-value pending orders as fully paid by making a minimal real PayPal payment and crafting an IPN whose `invoice` parameter references the targeted order, effectively completing purchases without tendering the required payment amount.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-29 10:00 UTC

CWE

CWE-345 - Insufficient Verification of Data Authenticity

Assigner

Wordfence mitre root

References

8 references

URL	Tags
https://www.wordfence.com/threat-intel/vulnerabil…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/browser/contac…
https://plugins.trac.wordpress.org/changeset/3551…

Impacted products

1 product

Vendor	Product	Version
scottpaterson	Contact Form 7 – PayPal & Stripe Add-on	Affected: 0 , ≤ 2.4.9 (semver)

Credits

Muni Nitish Kumar Yaddala

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-9189",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-29T10:00:42.885449Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-29T10:04:53.551Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Contact Form 7 \u2013 PayPal \u0026 Stripe Add-on",
          "vendor": "scottpaterson",
          "versions": [
            {
              "lessThanOrEqual": "2.4.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Muni Nitish Kumar Yaddala"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Contact Form 7 \u2013 PayPal \u0026 Stripe Add-on plugin for WordPress is vulnerable to Payment Bypass via Insufficient Verification of Data Authenticity in all versions up to, and including, 2.4.9. Although `cf7pp_paypal_ipn_handler()` correctly validates IPN authenticity by posting back to PayPal with `cmd=_notify-validate`, it fails to compare the IPN payload\u0027s `mc_gross` (payment amount), `mc_currency`, or `receiver_email` fields against the corresponding stored order values before passing the attacker-controlled `invoice` field directly to `cf7pp_complete_payment()`, which marks the order completed after only an integer cast with no amount verification. This makes it possible for unauthenticated attackers to mark arbitrary high-value pending orders as fully paid by making a minimal real PayPal payment and crafting an IPN whose `invoice` parameter references the targeted order, effectively completing purchases without tendering the required payment amount."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "CWE-345 Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-29T08:28:24.446Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5e274781-1c20-4224-bc10-26dadb9b1e07?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/paypal_handler.php#L106"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/paypal_handler.php#L75"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.8/includes/payments/functions.php#L31"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/paypal_handler.php#L106"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/paypal_handler.php#L75"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/contact-form-7-paypal-add-on/tags/2.4.6/includes/payments/functions.php#L31"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset/3551197/contact-form-7-paypal-add-on"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-05-21T15:22:09.000Z",
          "value": "Vendor Notified"
        },
        {
          "lang": "en",
          "time": "2026-05-28T19:54:04.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "Contact Form 7 \u2013 PayPal \u0026 Stripe Add-on \u003c= 2.4.9 - Unauthenticated Payment Bypass via Insufficient Verification of Data Authenticity via PayPal IPN Handler (\u0027invoice\u0027/\u0027mc_gross\u0027 Verification)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "cveId": "CVE-2026-9189",
    "datePublished": "2026-05-29T08:28:24.446Z",
    "dateReserved": "2026-05-21T15:06:53.761Z",
    "dateUpdated": "2026-05-29T10:04:53.551Z",
    "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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-VR4H-G9WJ-2P4G

CVE-2026-9189 (GCVE-0-2026-9189)

Tags

Sightings

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