Vulnerability-Lookup

GHSA-687M-WFRP-8MXF

Vulnerability from github – Published: 2026-09-11 12:33 – Updated: 2026-09-11 12:33

Details

The MetForm WordPress plugin before 4.1.9 does not properly neutralize newline characters in user-submitted values that are placed into notification email headers, allowing unauthenticated attackers to inject additional email headers, such as Bcc, into the emails the site sends when a submitted field value is configured to populate a header.

Severity

4.8 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-86813"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-93"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T11:16:57Z",
    "severity": "MODERATE"
  },
  "details": "The MetForm WordPress plugin before 4.1.9 does not properly neutralize newline characters in user-submitted values that are placed into notification email headers, allowing unauthenticated attackers to inject additional email headers, such as Bcc, into the emails the site sends when a submitted field value is configured to populate a header.",
  "id": "GHSA-687m-wfrp-8mxf",
  "modified": "2026-09-11T12:33:25Z",
  "published": "2026-09-11T12:33:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86813"
    },
    {
      "type": "WEB",
      "url": "https://wpscan.com/vulnerability/afda2a26-b965-42cb-85a8-4a4d83ec026e"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-86813 (GCVE-0-2026-86813)

Vulnerability from cvelistv5 – Published: 2026-09-11 10:56 – Updated: 2026-09-11 12:06

Title

MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To

Summary

Severity

4.8 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-11 12:05 UTC

CWE

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

Assigner

WPScan mitre root

References

1 reference

URL	Tags
https://wpscan.com/vulnerability/afda2a26-b965-42…	exploitvdb-entrytechnical-description

Impacted products

1 product

Vendor	Product	Version
Unknown	MetForm	Affected: 0 , < 4.1.9 (semver)

Credits

Artus KG WPScan

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-86813",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-11T12:05:38.615469Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-93",
                "description": "CWE-93 Improper Neutralization of CRLF Sequences (\u0027CRLF Injection\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-11T12:06:35.387Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://wordpress.org/plugins",
          "defaultStatus": "unaffected",
          "product": "MetForm",
          "vendor": "Unknown",
          "versions": [
            {
              "lessThan": "4.1.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Artus KG"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "WPScan"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The MetForm WordPress plugin before 4.1.9 does not properly neutralize newline characters in user-submitted values that are placed into notification email headers, allowing unauthenticated attackers to inject additional email headers, such as Bcc, into the emails the site sends when a submitted field value is configured to populate a header."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-93 Improper Neutralization of CRLF Sequences (\u0027CRLF Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T10:56:37.490Z",
        "orgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
        "shortName": "WPScan"
      },
      "references": [
        {
          "tags": [
            "exploit",
            "vdb-entry",
            "technical-description"
          ],
          "url": "https://wpscan.com/vulnerability/afda2a26-b965-42cb-85a8-4a4d83ec026e/"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "MetForm \u003c 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To",
      "x_generator": {
        "engine": "WPScan CVE Generator"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
    "assignerShortName": "WPScan",
    "cveId": "CVE-2026-86813",
    "datePublished": "2026-09-11T10:56:37.490Z",
    "dateReserved": "2026-09-08T13:37:59.083Z",
    "dateUpdated": "2026-09-11T12:06:35.387Z",
    "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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

GHSA-687M-WFRP-8MXF

CVE-2026-86813 (GCVE-0-2026-86813)

Tags

Sightings

Nomenclature