Description
Simple Machines Forum 2.1 prior to 2.1.8 and 3.0 prior to 3.0 Alpha 5 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.
Published: 2026-07-10
Score: 7.1 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Fri, 10 Jul 2026 16:30:00 +0000

Type Values Removed Values Added
Description Simple Machines Forum 2.1 prior to 2.1.8 and 3.0 prior to 3.0 Alpha 5 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.
Title Simple Machines Forum Authorization Bypass via AttachmentApprove.php
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L'}

cvssV4_0

{'score': 7.1, 'vector': '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'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-07-10T16:03:20.983Z

Reserved: 2026-04-07T20:57:06.209Z

Link: CVE-2026-39903

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses