CVE-2026-104890

Estado: AplazadaAlta (7.2)—

Kunstmaan CMS is an open source content management system based on the Symfony framework. Prior to 7.3.2, src/Kunstmaan/MediaBundle/Helper/File/FileHandler.php performs the blacklisted_extensions check case-sensitively in FileHandler::getFilePath and lowercases the stored extension afterward. An authenticated backend user with media access can upload a mixed-case executable extension such as PHP that bypasses the check and is stored in the web-accessible media directory with an executable lowercase extension. The default blacklist also omits several server-executable extension types, allowing the same code-execution impact where the web server executes uploaded files. This issue is fixed in version 7.3.2.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.2

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.42%
Percentil entre todas las CVEs puntuadas: 34
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement75 %
Impacto principalT1505.003 Web Shellpersistence85 %
Impacto secundarioT1059 Command and Scripting Interpreterexecution80 %

Acceso autenticado a servicio remoto (PR:H) sin interacción de usuario. Bypass de validación en carga de ficheros ejecutables (CWE-434) permite web shell en directorio accesible por el servidor web.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Disable or Remove Feature or Program Privileged Account Management Vulnerability Scanning User Account Management Threat Intelligence Program Restrict Web-Based Content

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Kunstmaan — Kunstmaan CMS^AI

CWE

CWE-434

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-104890",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.2,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.2
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "Kunstmaan",
          "product": "KunstmaanBundlesCMS",
          "versions": [
            {
              "status": "affected",
              "version": "< 7.3.1"
            }
          ]
        },
        {
          "vendor": "kunstmaan",
          "product": "bundles-cms",
          "versions": [
            {
              "status": "affected",
              "version": "< 7.3.1"
            }
          ]
        },
        {
          "vendor": "kunstmaan",
          "product": "media-bundle",
          "versions": [
            {
              "status": "affected",
              "version": "< 7.3.1"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-05T16:17:06.270",
  "references": [
    {
      "url": "https://github.com/Kunstmaan/KunstmaanBundlesCMS/commit/1bbdfdeac8e7e91506b1a9271360b9b68d7690d3",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/Kunstmaan/KunstmaanBundlesCMS/releases/tag/7.3.2",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/Kunstmaan/KunstmaanBundlesCMS/security/advisories/GHSA-p279-5wcv-45vq",
      "source": "security-advisories@github.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-434"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Kunstmaan CMS is an open source content management system based on the Symfony framework. Prior to 7.3.2, src/Kunstmaan/MediaBundle/Helper/File/FileHandler.php performs the blacklisted_extensions check case-sensitively in FileHandler::getFilePath and lowercases the stored extension afterward. An authenticated backend user with media access can upload a mixed-case executable extension such as PHP that bypasses the check and is stored in the web-accessible media directory with an executable lowercase extension. The default blacklist also omits several server-executable extension types, allowing the same code-execution impact where the web server executes uploaded files. This issue is fixed in version 7.3.2."
    }
  ],
  "lastModified": "2026-10-06T16:08:43.180",
  "sourceIdentifier": "security-advisories@github.com"
}