CVE-2026-43621

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.1 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.4% (28th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from the CNA's CVSS
Sources: the CNA's CVSS, EPSS
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.1Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100

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 (value × EchelonGraph’s weight)
Severity81% × 45%
The EG Score, 8.1 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
0.4%
EPSS %ILE
28th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 26, 2026

Last Modified

October 1, 2026

Advisory Details (2)

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

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 17× in last 7d / 99× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 178 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 78 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  3. 2026-10-12 16:06 UTCEG score recompute
  4. 2026-10-11 19:48 UTCEG score recompute
  5. 2026-10-11 17:02 UTCEG score recompute
  6. 2026-10-11 14:28 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  9. 2026-10-10 06:03 UTCEG score recompute
  10. 2026-10-10 06:03 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  12. 2026-10-09 03:19 UTCEG score recompute
  13. 2026-10-09 03:19 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  14. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  15. 2026-10-08 01:44 UTCEG score recompute
  16. 2026-10-08 01:44 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  18. 2026-10-07 07:08 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  19. 2026-10-06 19:16 UTCEG score recompute
  20. 2026-10-06 19:16 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  21. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  22. 2026-10-06 07:35 UTCEG score recompute
  23. 2026-10-06 07:35 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  24. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  25. 2026-10-05 16:54 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
Show 75 more
  1. 2026-10-05 03:44 UTCEG score recompute
  2. 2026-10-05 03:44 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  3. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  4. 2026-10-04 15:34 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  5. 2026-10-04 03:45 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  6. 2026-10-03 16:05 UTCEG score recompute
  7. 2026-10-03 16:05 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  8. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  9. 2026-10-03 03:17 UTCEG score recompute
  10. 2026-10-03 03:17 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  11. 2026-10-02 15:36 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  12. 2026-10-02 03:39 UTCEG score recompute
  13. 2026-10-02 03:39 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  14. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  15. 2026-10-01 15:28 UTCEG score recompute
  16. 2026-10-01 15:28 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  17. 2026-10-01 07:37 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  18. 2026-09-30 19:57 UTCEG score recompute
  19. 2026-09-30 19:57 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  20. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  21. 2026-09-30 06:00 UTCEG score recompute
  22. 2026-09-30 06:00 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  23. 2026-09-29 12:25 UTCEG score recompute
  24. 2026-09-29 12:25 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  25. 2026-09-28 21:20 UTCEG score recompute
  26. 2026-09-28 21:20 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  27. 2026-09-28 07:36 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  28. 2026-09-27 19:56 UTCEG score recompute
  29. 2026-09-27 19:56 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  30. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  31. 2026-09-27 08:16 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  32. 2026-09-26 20:30 UTCEG score recompute
  33. 2026-09-26 20:30 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  34. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  35. 2026-09-25 08:17 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  36. 2026-09-24 20:35 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  37. 2026-09-24 18:48 UTCEG score recompute
  38. 2026-09-24 18:48 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  39. 2026-09-24 05:56 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  40. 2026-09-23 18:15 UTCEG score recompute
  41. 2026-09-23 18:15 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  42. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  43. 2026-09-23 06:35 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  44. 2026-09-22 18:54 UTCEG score recompute
  45. 2026-09-22 18:54 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  46. 2026-09-22 07:14 UTCEG score recompute
  47. 2026-09-22 07:14 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  48. 2026-09-21 19:34 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  49. 2026-09-21 07:54 UTCEG score recompute
  50. 2026-09-21 07:54 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  51. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  52. 2026-09-20 20:14 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  53. 2026-09-20 08:33 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  54. 2026-09-19 20:53 UTCEG score recompute
  55. 2026-09-19 20:53 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  56. 2026-09-19 09:12 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  57. 2026-09-18 21:31 UTCEG score recompute
  58. 2026-09-18 21:31 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  59. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  60. 2026-09-18 08:37 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  61. 2026-09-17 20:57 UTCEG score recompute
  62. 2026-09-17 20:57 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  63. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  64. 2026-09-17 09:12 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  65. 2026-09-16 21:31 UTCEG score recompute
  66. 2026-09-16 21:31 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  67. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  68. 2026-09-16 09:18 UTCEG score recompute
  69. 2026-09-16 09:18 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  70. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  71. 2026-09-15 21:07 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  72. 2026-09-15 09:26 UTCEG score recompute
  73. 2026-09-15 09:26 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  74. 2026-09-14 21:45 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH
  75. 2026-09-14 10:04 UTCGHSA enrichmentGHSA-pw24-wq86-2799 · GitHub severity HIGH

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-43621?
CVE-2026-43621 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2026-43621 was made public on July 15, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 26, 2026. EchelonGraph's copy of the record carries a last-modified date of October 1, 2026; the record at its source may have been updated since.
Is CVE-2026-43621 actively exploited?
CVE-2026-43621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43621?
CVE-2026-43621 has a CVSS base score of 8.1 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-43621?
An upstream fix for CVE-2026-43621 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-43621 are linked in the Vendor Advisories panel on this page.

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