CVE-2026-43621

Simple Machines Forum < 2.1.7 Authorization Confusion via Profile::load()

Published Aug 26, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
Description
Simple Machines Forum (SMF) through 2.1.7, fixed in commit 6f0dc61, contains an authorization state-confusion vulnerability in the profile loader that allows authenticated low-privileged users to gain administrator access by supplying multiple values for the user parameter. Attackers can exploit the mismatch between Profile::$member and User::$me->is_owner during sequential profile loading to be treated as the owner of an administrator profile, enabling unauthorized password changes and full account takeover.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Simplemachines simple Machines Forum
CPEs cpe:2.3:a:simplemachines:simple_machines_forum:*:*:*:*:*:*:*:*
Vendors & Products Simplemachines simple Machines Forum
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 0, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N'}

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

Type Values Removed Values Added
First Time appeared Simplemachines
Simplemachines smf
Vendors & Products Simplemachines
Simplemachines smf
Type Values Removed Values Added
Description Simple Machines Forum (SMF) through 2.1.7, fixed in commit 6f0dc61, contains an authorization state-confusion vulnerability in the profile loader that allows authenticated low-privileged users to gain administrator access by supplying multiple values for the user parameter. Attackers can exploit the mismatch between Profile::$member and User::$me->is_owner during sequential profile loading to be treated as the owner of an administrator profile, enabling unauthorized password changes and full account takeover.
Title Simple Machines Forum < 2.1.7 Authorization Confusion via Profile::load()
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 0, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 1, 2026, 3:20 PM
Reserved
May 1, 2026, 6:22 PM
Status
Awaiting Analysis
Published
Aug 26, 2026, 10:16 PM
Modified
Sep 24, 2026, 8:28 PM