CVE-2026-43621highCWE-863

CVE-2026-43621: high-severity vulnerability in SimpleMachines SMF

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

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41Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 8.6epss 0.4%
from disclosure to weapon62 days
Published on NVDAug 26
1st PoC+62d
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.
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
Affected products
SimpleMachines · SMF
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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