CVE-2026-40020

{
  "id": "CVE-2026-40020",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-12T14:17:03.687",
  "lastModified": "2026-10-26T18:10:00.173",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Attacker can use the IMAP SETACL command to inject the anyone permission to user's dovecot-acl file even if imap_acl_allow_anyone=no. This causes folders to be spammed to all users. The impact is limited to being able to spam folders to other users, no unexpected access is gained. Install to fixed version. No publicly available exploits are known."
    },
    {
      "lang": "es",
      "value": "El atacante puede usar el comando IMAP SETACL para inyectar el permiso anyone en el archivo dovecot-acl del usuario incluso si imap_acl_allow_anyone=no. Esto provoca que las carpetas sean enviadas como correo no deseado a todos los usuarios. El impacto se limita a poder enviar carpetas como correo no deseado a otros usuarios; no se obtiene acceso inesperado. Instale la versión corregida. No se conocen exploits disponibles públicamente."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Open-Xchange GmbH",
          "product": "OX Dovecot Pro",
          "defaultStatus": "unaffected",
          "modules": [
            "core"
          ],
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "2.3.0",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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        "source": "[email protected]",
        "type": "Secondary",
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          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 3.1,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 1.4
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
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          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-12T15:40:03.182471Z",
          "id": "CVE-2026-40020",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        }
      ]
    },
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "configurations": [
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      "nodes": [
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          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
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  "references": [
    {
      "url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}