CVE-2026-91831 (GCVE-0-2026-91831)

Vulnerability from cvelistv5 – Published: 2026-10-19 06:46 – Updated: 2026-10-19 09:31
VLAI
Title
Subscribe to Comments 2.3 - 2.3.2 - Author+ Email Header Injection via From Name Setting
Summary
The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender.
Severity
3.8 (Low)
CVSS:3.1/AV:N/AC:L/PR:H/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 2026-10-19 09:25 UTC
CWE
Assigner
WPScan CNA under the mitre root
CNA scorecard E 44/100 over 1723 records in the last 180 days details
References
URL Tags
https://wpscan.com/vulnerability/6cd60f78-f5e2-4b… exploitvdb-entrytechnical-description
Impacted products
Vendor Product Version CPE status
Unknown Subscribe to Comments Affected: 2.3 , < 2.3.3 (semver)
guessed Create a notification for this product.
Credits
Het Kalariya WPScan
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-91831",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-19T09:25:57.636205Z",
                "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": "2026-10-19T09:31:21.214Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://wordpress.org/plugins",
          "defaultStatus": "unaffected",
          "product": "Subscribe to Comments",
          "vendor": "Unknown",
          "versions": [
            {
              "lessThan": "2.3.3",
              "status": "affected",
              "version": "2.3",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Het Kalariya"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "WPScan"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 3.8,
            "baseSeverity": "LOW",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/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": "2026-10-19T06:46:17.280Z",
        "orgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
        "shortName": "WPScan"
      },
      "references": [
        {
          "tags": [
            "exploit",
            "vdb-entry",
            "technical-description"
          ],
          "url": "https://wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Subscribe to Comments 2.3 - 2.3.2 - Author+ Email Header Injection via From Name Setting",
      "x_generator": {
        "engine": "WPScan CVE Generator"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
    "assignerShortName": "WPScan",
    "cveId": "CVE-2026-91831",
    "datePublished": "2026-10-19T06:46:17.280Z",
    "dateReserved": "2026-09-15T08:14:21.129Z",
    "dateUpdated": "2026-10-19T09:31:21.214Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-91831",
      "date": "2026-10-19",
      "epss": "0.00161",
      "percentile": "0.04878"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://wordpress.org/plugins",
                "defaultStatus": "unaffected",
                "product": "Subscribe to Comments",
                "vendor": "Unknown",
                "versions": [
                  {
                    "lessThan": "2.3.3",
                    "status": "affected",
                    "version": "2.3",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "contact@wpscan.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender."
          }
        ],
        "id": "CVE-2026-91831",
        "lastModified": "2026-10-19T21:02:51.987",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 3.8,
                "baseSeverity": "LOW",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "HIGH",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.2,
              "impactScore": 2.5,
              "source": "contact@wpscan.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-91831",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-19T09:25:57.636205Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-10-19T07:16:32.187",
        "references": [
          {
            "source": "contact@wpscan.com",
            "url": "https://wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/"
          }
        ],
        "sourceIdentifier": "contact@wpscan.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-93"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-91831",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-10-19T09:25:57.636205Z",
                    "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": "2026-10-19T09:25:19.879Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "collectionURL": "https://wordpress.org/plugins",
              "defaultStatus": "unaffected",
              "product": "Subscribe to Comments",
              "vendor": "Unknown",
              "versions": [
                {
                  "lessThan": "2.3.3",
                  "status": "affected",
                  "version": "2.3",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "finder",
              "value": "Het Kalariya"
            },
            {
              "lang": "en",
              "type": "coordinator",
              "value": "WPScan"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "baseScore": 3.8,
                "baseSeverity": "LOW",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/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": "2026-10-19T06:46:17.280Z",
            "orgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
            "shortName": "WPScan"
          },
          "references": [
            {
              "tags": [
                "exploit",
                "vdb-entry",
                "technical-description"
              ],
              "url": "https://wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/"
            }
          ],
          "source": {
            "discovery": "EXTERNAL"
          },
          "title": "Subscribe to Comments 2.3 - 2.3.2 - Author+ Email Header Injection via From Name Setting",
          "x_generator": {
            "engine": "WPScan CVE Generator"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
        "assignerShortName": "WPScan",
        "cveId": "CVE-2026-91831",
        "datePublished": "2026-10-19T06:46:17.280Z",
        "dateReserved": "2026-09-15T08:14:21.129Z",
        "dateUpdated": "2026-10-19T09:31:21.214Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.