FKIE_CVE-2026-39903

Vulnerability from fkie_nvd - Published: 2026-07-10 17:16 - Updated: 2026-10-25 15:10
Severity
7.1 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Summary
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.
References
disclosure@vulncheck.comhttps://github.com/SimpleMachines/SMF/commit/7d048f8d66aab9af51cd6ee110fbad103cf673e8
disclosure@vulncheck.comhttps://github.com/SimpleMachines/SMF/commit/a7875e876a647572dd4c45da881b875092caac3d
disclosure@vulncheck.comhttps://github.com/SimpleMachines/SMF/pull/9181
disclosure@vulncheck.comhttps://github.com/SimpleMachines/SMF/pull/9182
disclosure@vulncheck.comhttps://www.vulncheck.com/advisories/simple-machines-forum-authorization-bypass-via-attachmentapprove-php
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "affected",
          "packageURL": "pkg:github/SimpleMachines/SMF",
          "product": "SMF",
          "repo": "https://github.com/SimpleMachines/SMF",
          "vendor": "SimpleMachines",
          "versions": [
            {
              "lessThanOrEqual": "2.1.7",
              "status": "affected",
              "version": "2.1.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7d048f8d66aab9af51cd6ee110fbad103cf673e8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "a7875e876a647572dd4c45da881b875092caac3d",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "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\u0027 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 autorizaci\u00f3n en Sources/Actions/AttachmentApprove.php donde un error de operador de un solo car\u00e1cter causa que la verificaci\u00f3n 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 moderaci\u00f3n para sus propias cargas, y enumerar y eliminar los archivos adjuntos pendientes de otros usuarios."
    }
  ],
  "id": "CVE-2026-39903",
  "lastModified": "2026-10-25T15:10:00.147",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.2,
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "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",
          "version": "4.0",
          "vulnAvailabilityImpact": "LOW",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-39903",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-14T01:56:17.608329Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-10T17:16:57.230",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/SimpleMachines/SMF/commit/7d048f8d66aab9af51cd6ee110fbad103cf673e8"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/SimpleMachines/SMF/commit/a7875e876a647572dd4c45da881b875092caac3d"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/SimpleMachines/SMF/pull/9181"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/SimpleMachines/SMF/pull/9182"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/simple-machines-forum-authorization-bypass-via-attachmentapprove-php"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Secondary"
    }
  ]
}



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