CVE-2026-39903

{
  "id": "CVE-2026-39903",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-10T17:16:57.230",
  "lastModified": "2026-10-25T15:10:00.147",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Simple Machines Forum 2.1 prior to commit 7d048f8 and 3.0 prior to commit a7875e8 contains an authorization bypass vulnerability in Sources/Actions/AttachmentApprove.php where a single-character operator error causes the permission check to always pass regardless of user permissions. An authenticated low-privileged user can approve, reject, or delete any pending attachments on any board without holding the required approve_posts permission, bypass moderation queues for their own uploads, and enumerate and delete other users' pending attachments."
    },
    {
      "lang": "es",
      "value": "Simple Machines Forum 2.1 anterior a 2.1.8 y 3.0 anterior a 3.0 Alpha 5 contiene una vulnerabilidad de bypass de autorización en Sources/Actions/AttachmentApprove.php donde un error de operador de un solo carácter causa que la verificación de permisos siempre pase independientemente de los permisos del usuario. Un usuario autenticado con bajos privilegios puede aprobar, rechazar o eliminar cualquier archivo adjunto pendiente en cualquier foro sin poseer el permiso approve_posts requerido, eludir las colas de moderación para sus propias cargas, y enumerar y eliminar los archivos adjuntos pendientes de otros usuarios."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "SimpleMachines",
          "product": "SMF",
          "defaultStatus": "affected",
          "repo": "https://github.com/SimpleMachines/SMF",
          "packageURL": "pkg:github/SimpleMachines/SMF",
          "versions": [
            {
              "version": "2.1.0",
              "lessThanOrEqual": "2.1.7",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "7d048f8d66aab9af51cd6ee110fbad103cf673e8",
              "versionType": "git",
              "status": "unaffected"
            },
            {
              "version": "3.0.0",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "a7875e876a647572dd4c45da881b875092caac3d",
              "versionType": "git",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/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": 7.1,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "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"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-14T01:56:17.608329Z",
          "id": "CVE-2026-39903",
          "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-863"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/SimpleMachines/SMF/commit/7d048f8d66aab9af51cd6ee110fbad103cf673e8",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/SimpleMachines/SMF/commit/a7875e876a647572dd4c45da881b875092caac3d",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/SimpleMachines/SMF/pull/9181",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/SimpleMachines/SMF/pull/9182",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/simple-machines-forum-authorization-bypass-via-attachmentapprove-php",
      "source": "[email protected]"
    }
  ]
}