CVE-2026-43621 — HIGH (8.1)

Vulnerability 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.

CVSS Score

8.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Related Weaknesses (CWE)

CWE-863

References

FAQ

What is CVE-2026-43621?

CVE-2026-43621 is a vulnerability with a CVSS score of 8.1 (HIGH). 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...

How severe is CVE-2026-43621?

CVE-2026-43621 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-43621?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.