CVE-2026-39903

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.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/SimpleMachines/SMF/commit/7d048f8d66aab9af51cd6ee110fbad103cf673e8
https://github.com/SimpleMachines/SMF/commit/a7875e876a647572dd4c45da881b875092caac3d
https://github.com/SimpleMachines/SMF/pull/9181
https://github.com/SimpleMachines/SMF/pull/9182
https://www.vulncheck.com/advisories/simple-machines-forum-authorization-bypass-via-attachmentapprove-php

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-10 17:16

Updated : 2026-07-14 21:16

NVD link : CVE-2026-39903

Mitre link : CVE-2026-39903

CVE.ORG link : CVE-2026-39903

JSON object : View

Products Affected

No product.

CWE

CWE-863

Incorrect Authorization

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