CVE-2026-53902

Full vulnerability record from the local CVENow database.

Description

MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation. An attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques. Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.

Severity

HIGH

CVSS score

7.1 (v4.0)

Vulnerability status

Analyzed

Source identifier

[email protected]

Published

2026-07-01 13:17:45.237000

Last modified

2026-10-25 17:10:00.197000

View original CVE JSON

{
  "id": "CVE-2026-53902",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-01T13:17:45.237",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated user can modify their group membership without proper authorization checks, allowing privilege escalation.\nAn attacker can add themselves to arbitrary groups by supplying a valid group ID, which can be obtained via other application functionalities (e.g. /customer/servlet/mco/webapi/group/picker/groups), provided he has necessary permissions, or potentially inferred through brute-force techniques.\n\n\n\nBecause vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions."
    },
    {
      "lang": "es",
      "value": "MCO no aplica correctamente las comprobaciones de autorización en el endpoint /customer/servlet/mco/webapi/profile-sections/group-membership. Un usuario autenticado puede modificar su pertenencia a grupos sin las comprobaciones de autorización adecuadas, permitiendo la escalada de privilegios.\nUn atacante puede añadirse a grupos arbitrarios proporcionando un ID de grupo válido, que puede obtenerse a través de otras funcionalidades de la aplicación (por ejemplo, /customer/servlet/mco/webapi/group/picker/groups), siempre que tenga los permisos necesarios, o potencialmente inferirse mediante técnicas de fuerza bruta.\n\nDebido a que los intentos de contacto con el proveedor no tuvieron éxito, la vulnerabilidad solo se ha confirmado en la versión 25.3.3.1, pero también puede afectar a otras versiones."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "MyComplianceOffice",
          "product": "MCO",
          "defaultStatus": "unknown",
          "versions": [
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              "versionType": "custom",
              "status": "affected"
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          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
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          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
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          "valueDensity": "NOT_DEFINED",
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    "ssvcV203": [
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  "references": [
    {
      "url": "https://cert.pl/en/posts/2026/07/CVE-2026-53902",
      "source": "[email protected]",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://mco.mycomplianceoffice.com/",
      "source": "[email protected]",
      "tags": [
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}