FKIE_CVE-2023-46251

Vulnerability from fkie_nvd - Published: 2023-11-06 18:15 - Updated: 2026-06-17 06:30
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
6.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Summary
MyBB is a free and open source forum software. Custom MyCode (BBCode) for the visual editor (_SCEditor_) doesn't escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. This weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. The impact is be mitigated when: 1. the visual editor is disabled globally (_Admin CP → Configuration → Settings → Clickable Smilies and BB Code: [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_ is set to _Off_), or 2. the visual editor is disabled for individual user accounts (_User CP → Your Profile → Edit Options_: _Show the MyCode formatting options on the posting pages_ checkbox is not checked). MyBB 1.8.37 resolves this issue with the commit `6dcaf0b4d`. Users are advised to upgrade. Users unable to upgrade may mitigate the impact without upgrading MyBB by changing the following setting (_Admin CP → Configuration → Settings_): - _Clickable Smilies and BB Code → [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_: _Off_. Similarly, individual MyBB forum users are able to disable the visual editor by diabling the account option (_User CP → Your Profile → Edit Options_) _Show the MyCode formatting options on the posting pages_.
References
security-advisories@github.comhttps://github.com/mybb/mybb/commit/6dcaf0b4db6254f1833fe8dae295d9ddc2219276Patch
security-advisories@github.comhttps://github.com/mybb/mybb/security/advisories/GHSA-wj33-q7vj-9fr8Vendor Advisory
security-advisories@github.comhttps://mybb.com/versions/1.8.37/Release Notes
af854a3a-2127-422b-91ae-364da2661108https://github.com/mybb/mybb/commit/6dcaf0b4db6254f1833fe8dae295d9ddc2219276Patch
af854a3a-2127-422b-91ae-364da2661108https://github.com/mybb/mybb/security/advisories/GHSA-wj33-q7vj-9fr8Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://mybb.com/versions/1.8.37/Release Notes
Impacted products
Vendor Product Version
mybb mybb *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mybb",
          "vendor": "mybb",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.8.37"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    },
    {
      "affectedData": [
        {
          "cpes": [
            "cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unknown",
          "product": "mybb",
          "vendor": "mybb",
          "versions": [
            {
              "lessThan": "1.8.37",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "EC8DBC6D-0D47-46D6-A840-36BF42F37437",
              "versionEndExcluding": "1.8.37",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": " MyBB is a free and open source forum software. Custom MyCode (BBCode) for the visual editor (_SCEditor_) doesn\u0027t escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. This weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. The impact is be mitigated when: 1. the visual editor is disabled globally (_Admin CP \u2192 Configuration \u2192 Settings \u2192 Clickable Smilies and BB Code: [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_ is set to _Off_), or 2. the visual editor is disabled for individual user accounts (_User CP \u2192 Your Profile \u2192 Edit Options_: _Show the MyCode formatting options on the posting pages_ checkbox is not checked). MyBB 1.8.37 resolves this issue with the commit `6dcaf0b4d`. Users are advised to upgrade. Users unable to upgrade may mitigate the impact without upgrading MyBB by changing the following setting (_Admin CP \u2192 Configuration \u2192 Settings_):\n- _Clickable Smilies and BB Code \u2192 [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_: _Off_. Similarly, individual MyBB forum users are able to disable the visual editor by diabling the account option (_User CP \u2192 Your Profile \u2192 Edit Options_) _Show the MyCode formatting options on the posting pages_."
    },
    {
      "lang": "es",
      "value": "MyBB es un software de foro gratuito y de c\u00f3digo abierto. El MyCode personalizado (BBCode) para el editor visual (_SCEditor_) no sanitiza la entrada correctamente al representar HTML, lo que genera una vulnerabilidad XSS basada en DOM. Esta debilidad se puede explotar dirigiendo a la v\u00edctima a una p\u00e1gina donde el editor visual est\u00e1 activo (por ejemplo, como una publicaci\u00f3n o mensaje privado) y opera con un mensaje MyCode creado con fines malintencionados. Esto puede ocurrir en p\u00e1ginas donde el contenido del mensaje se completa previamente mediante un par\u00e1metro GET/POST, o en p\u00e1ginas de respuesta donde se cita un mensaje malicioso previamente guardado. El impacto se mitiga cuando: \n1. el editor visual est\u00e1 deshabilitado globalmente (_Admin CP ? Configuration ? Settings ? Clickable Smilies and BB Code: [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_ is set to _Off_), o \n2. el editor visual est\u00e1 deshabilitado para cuentas de usuario individuales (_User CP ? Your Profile ? Edit Options_: _Show the MyCode formatting options on the posting pages_ checkbox is not checked).\nMyBB 1.8.37 resuelve este problema con el commit `6dcaf0b4d`. Se recomienda a los usuarios que actualicen. Los usuarios que no puedan actualizar pueden mitigar el impacto sin actualizar MyBB cambiando la siguiente configuraci\u00f3n (_Admin CP ? Configuration ? Settings_): - _Clickable Smilies and BB Code ? [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_: _Off_. \nDe manera similar, los usuarios individuales del foro MyBB pueden desactivar el editor visual marcando la opci\u00f3n de cuenta (_User CP ? Your Profile ? Edit Options_)_Show the MyCode formatting options on the posting pages_."
    }
  ],
  "id": "CVE-2023-46251",
  "lastModified": "2026-06-17T06:30:31.310",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.9,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-46251",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-09-04T19:26:53.568111Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2023-11-06T18:15:08.547",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mybb/mybb/commit/6dcaf0b4db6254f1833fe8dae295d9ddc2219276"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/mybb/mybb/security/advisories/GHSA-wj33-q7vj-9fr8"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://mybb.com/versions/1.8.37/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mybb/mybb/commit/6dcaf0b4db6254f1833fe8dae295d9ddc2219276"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/mybb/mybb/security/advisories/GHSA-wj33-q7vj-9fr8"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Release Notes"
      ],
      "url": "https://mybb.com/versions/1.8.37/"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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