CVE-2026-43621

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 5 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
8.1
EG Score
8.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Aug 26, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

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

https://www.vulncheck.com/advisories/simple-machines-forum-authorization-confusion-via-profile-load
github_commit

commit 6f0dc61958aa (SimpleMachines/SMF)

Fix landed in SimpleMachines/SMF commit 6f0dc61958aa — awaiting tagged release

https://github.com/SimpleMachines/SMF/commit/6f0dc61958aa86a4b436a222f6176812ed5bbb95

Vendor Advisories for CVE-2026-43621(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 20:06 UTCGHSA enrichment
  3. 2026-08-29 08:24 UTCEG score recompute
  4. 2026-08-29 08:24 UTCGHSA enrichment
  5. 2026-08-28 21:41 UTCEPSS rescore
  6. 2026-08-28 20:44 UTCGHSA enrichment
  7. 2026-08-28 16:41 UTCEG score recompute
  8. 2026-08-28 16:41 UTCGHSA enrichment
  9. 2026-08-28 15:47 UTCEG score recompute▼ 0.50
  10. 2026-08-28 15:46 UTCGHSA enrichment
  11. 2026-08-28 15:25 UTCMITRE cvelistV5CVSS v3 → 8.1 · severity → HIGH
  12. 2026-08-28 09:32 UTCGHSA enrichment
  13. 2026-08-27 21:47 UTCEG score recompute
  14. 2026-08-27 21:47 UTCGHSA enrichment
  15. 2026-08-27 14:25 UTCEPSS rescore
  16. 2026-08-27 10:06 UTCGHSA enrichment
  17. 2026-08-26 22:24 UTCEG score recompute
  18. 2026-08-26 22:24 UTCNVD update
  19. 2026-08-26 22:02 UTCEG score recompute
  20. 2026-08-26 22:01 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-43621?
CVE-2026-43621 is a high vulnerability published on August 26, 2026. 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…
When was CVE-2026-43621 disclosed?
CVE-2026-43621 was first published in the National Vulnerability Database on August 26, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43621 actively exploited?
CVE-2026-43621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 89.1% of all scored CVEs.
What is the CVSS score of CVE-2026-43621?
CVE-2026-43621 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-43621?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43621, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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