CVE-2026-53599

Estado: AplazadaAlta (7.5)—

REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.51%
Percentil entre todas las CVEs puntuadas: 41
Fecha de la puntuación: 3/10/2026

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 %
Impacto secundarioT1068 Exploitation for Privilege Escalationprivilege escalation70 %

Usuario autenticado (PR:L) explota validación débil de extensiones para subir polyglot JPEG/PHP ejecutable como web shell, logrando RCE con permisos del servidor web. CWE-434 (unrestricted upload) + respuesta multiextensión confirma acceso a servicios remotos internos desde posición privilegiada.

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 Threat Intelligence Program Privileged Account Management Execution Prevention Application Isolation and Sandboxing Exploit Protection

Tecnologías afectadas (1)

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

Redaxo — Redaxo^AI

CWE

CWE-434

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-53599",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-53599",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-31T20:11:41.826930Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.6
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "redaxo",
          "product": "core",
          "versions": [
            {
              "status": "affected",
              "version": ">= 5.18.2, < 5.21.1"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-07-31T20:16:51.847",
  "references": [
    {
      "url": "https://github.com/redaxo/core/commit/462e36896bb65d292ba22d711044c23c9cfb0340",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/redaxo/core/pull/6538",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/redaxo/core/releases/tag/5.21.1",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-434"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1."
    }
  ],
  "lastModified": "2026-09-09T20:55:04.493",
  "sourceIdentifier": "security-advisories@github.com"
}