CVE-2026-40875

{
  "id": "CVE-2026-40875",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-21T20:17:01.120",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the user dashboard's \"Seen successful connections\" (login history) renders the client IP from login logs without HTML escaping. Because the server trusts the X-Real-IP header as the source IP for logging, an attacker can inject HTML/JS into this field. This Self-XSS can be exploited by a Login CSRF to force the victim into the attacker's account, and then read emails in a previous browser tab. Version 2026-03b fixes the vulnerability."
    },
    {
      "lang": "es",
      "value": "mailcow: dockerized es una suite de groupware/correo electrónico de código abierto basada en docker. En versiones anteriores a 2026-03b, el panel de usuario ’Conexiones exitosas vistas’ (historial de inicio de sesión) muestra la IP del cliente de los registros de inicio de sesión sin escape HTML. Debido a que el servidor confía en el encabezado X-Real-IP como la IP de origen para el registro, un atacante puede inyectar HTML/JS en este campo. Este Self-XSS puede ser explotado mediante un CSRF de inicio de sesión para forzar a la víctima a la cuenta del atacante, y luego leer correos electrónicos en una pestaña de navegador anterior. La versión 2026-03b corrige la vulnerabilidad."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "mailcow",
          "product": "mailcow-dockerized",
          "versions": [
            {
              "version": "< 2026-03b",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "LOW",
          "userInteraction": "PASSIVE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "HIGH",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-04-21T19:53:02.686540Z",
          "id": "CVE-2026-40875",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        },
        {
          "lang": "en",
          "value": "CWE-80"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}