← Vulnerability feed

Vulnerability record · CVE-2026-39903 · published 10 July 2026

CVE-2026-39903: Incorrect authorization vulnerability

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.

7.1 CVSS 4.0 High EPSS 0.47% · top 62.1% CWE-863 · Incorrect authorization Deferred
7.1CVSS 4.0 base score
0.47%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
5References
14 Jul 2026Last modified by NVD

Description

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: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:

References

LinkTags
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

Track CVE-2026-39903 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2026-71362Adobe commerce incorrect authorization vulnerabilityAdobe Commerce is affected by an Incorrect Authorization vulnerability that could result in privilege escalation. An attacker could leverage this vul…KEVEPSS 88%8.8CVE-2026-42016JFrog Artifactory token scope bypass enables privilege escalationJFrog Artifactory (Self Hosted) before 7.133.11 validates a token's signature and issuer but not its scope, so a token can be used for actions beyond…KEVEPSS 8.6%analysed10.0CVE-2025-54253Adobe Experience Manager Forms misconfiguration allows pre-auth code executionAdobe Experience Manager Forms 6.5.23 and earlier contain a misconfiguration (CWE-863, incorrect authorization) that lets an attacker bypass security…KEVEPSS 88%analysed5.4CVE-2025-55177WhatsApp iOS and Mac linked-device sync authorization flawWhatsApp for iOS, WhatsApp Business for iOS and WhatsApp for Mac fail to fully authorize linked-device synchronization messages, letting an unrelated…KEVEPSS 4.3%analysed8.6CVE-2025-21480Qualcomm GPU micronode memory corruption via unauthorized command executionA memory corruption flaw in Qualcomm's GPU micronode is caused by incorrect authorization (CWE-863), allowing an unauthorized command sequence to be …KEVEPSS 0.46%analysed8.6CVE-2025-21479Qualcomm GPU micronode memory corruption via unauthorized command executionQualcomm chipsets contain an incorrect authorization flaw in the GPU micronode that allows memory corruption when a specific sequence of commands is …KEVEPSS 0.84%analysed6.1CVE-2025-24200Apple iOS and iPadOS authorization flaw disables USB Restricted ModeAn incorrect authorization issue in Apple iOS and iPadOS is addressed through improved state management. A physical attacker can disable USB Restrict…KEVEPSS 4.5%analysed7.5CVE-2024-21287Oracle Agile PLM Framework incorrect authorization exposes dataOracle Agile PLM Framework 9.3.6 contains an incorrect authorization flaw in the Software Development Kit / Process Extension component. An unauthent…KEVEPSS 1.7%analysed

Source: NIST National Vulnerability Database (record CVE-2026-39903), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.