CVE-2026-43621Network attack vector

Administrator account takeover via profile state confusion

Published Aug 26, 2026 · Updated Aug 28, 2026

Incorrect authorization in Simple Machines Forum 2.1.7 and earlier allows remote authenticated users to take over administrator accounts. Multiple user-parameter values make sequential profile loads leave the loaded-member object and current-user ownership flag associated with different accounts. A low-privileged account is consequently treated as the owner of an administrator profile and can replace the administrator's password.

CVSS severity8.6
High
EPSS probability0.21%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Simple Machines Forum 2.1.7 and earlier allows remote authenticated users to take over administrator accounts. Multiple user-parameter values make sequential profile loads leave the loaded-member object and current-user ownership flag associated with different accounts. A low-privileged account is consequently treated as the owner of an administrator profile and can replace the administrator's password.

The record

CVE
CVE-2026-43621
Published
Aug 26, 2026
Updated
Aug 28, 2026
Vendor
free5GC
Product
SMF
Classifications
CWE-863, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.1.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

free5GC · SMFversion=0 <=2.1.7

Published CVSS scores

8.6VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
0.0VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1098Account Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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