CVE-2026-45129

MEDIUMPre-NVD 4.64.6
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 4.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (7th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
4.6EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.6Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Recovery Codes module does not validate requests correctly, allowing same-site attackers to rotate a victim administrator's recovery codes with a specially crafted URL. The Admin CP Home, Preferences, Recovery Codes action=recovery_codes page regenerates Two-Factor Authentication recovery codes in mybb_adminoptions.recovery_codes on GET requests without request forgery protection. The uniquely identifying implementation details include admin/modules/home/preferences.php. This issue is fixed in version 1.8.40.

CVSS v3
4.6
EG Score
4.6MEDIUMmedium confidence
EG Risk
21
EG Risk 21/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity46% × 45%
Impact severity (EG Severity): CVSS 4.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
7th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (4.6): severity, escalated by confirmed exploitation. This CVE's 4.6 is its impact severity (EG Severity), not escalated.

EG Severity
4.6 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-22). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines.

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 18, 2026

Last Modified

September 8, 2026

Advisory Details (4)

Auto-updated Aug 18, 2026
Patch available. Sources: github, github_commit, github_release.
Web page

Version 1.8.40 - MyBB

https://mybb.com/versions/1.8.40
GitHub release Patch Available

mybb_1840

Patch available: mybb/mybb mybb_1840

https://github.com/mybb/mybb/releases/tag/mybb_1840
GitHub commit Patch Available

commit d2d9e47b53d8 (mybb/mybb)

Patch available: mybb/mybb mybb_1840 (contains commit d2d9e47b53d8)

https://github.com/mybb/mybb/commit/d2d9e47b53d85101cf25cb47e882bc7ba76355a4
GitHub advisoryMentions a patch (unverified)

ACP Recovery Codes CSRF · Advisory · mybb/mybb · GitHub

https://github.com/mybb/mybb/security/advisories/GHSA-75vg-6wgp-mcc9

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 42× 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 106 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 6 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  2. 2026-10-22 23:37 UTCEG score recompute
  3. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  4. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  5. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  6. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  8. 2026-10-18 03:38 UTCEG score recompute
  9. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  11. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  15. 2026-10-12 16:04 UTCEG score recompute
  16. 2026-10-11 19:46 UTCEG score recompute
  17. 2026-10-11 17:01 UTCEG score recompute
  18. 2026-10-11 14:26 UTCEG score recompute
  19. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-10-07 08:49 UTCEG score recompute
  25. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 7th percentile
Show 75 more
  1. 2026-10-06 08:23 UTCEG score recompute
  2. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  4. 2026-10-03 17:39 UTCEG score recompute
  5. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  6. 2026-10-02 10:21 UTCEG score recompute
  7. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  8. 2026-10-01 10:05 UTCEG score recompute
  9. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-09-30 09:49 UTCEG score recompute
  11. 2026-09-29 08:27 UTCEG score recompute
  12. 2026-09-28 08:12 UTCEG score recompute
  13. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-09-27 07:56 UTCEG score recompute
  15. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-09-25 07:10 UTCEG score recompute
  17. 2026-09-24 06:51 UTCEG score recompute
  18. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  19. 2026-09-23 06:34 UTCEG score recompute
  20. 2026-09-22 06:18 UTCEG score recompute
  21. 2026-09-21 06:03 UTCEG score recompute
  22. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  23. 2026-09-20 04:30 UTCEG score recompute
  24. 2026-09-19 04:14 UTCEG score recompute
  25. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  26. 2026-09-18 03:59 UTCEG score recompute
  27. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  28. 2026-09-17 03:43 UTCEG score recompute
  29. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  30. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  31. 2026-09-16 02:50 UTCEG score recompute
  32. 2026-09-14 02:10 UTCEG score recompute
  33. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  34. 2026-09-13 01:55 UTCEG score recompute
  35. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  36. 2026-09-12 01:39 UTCEG score recompute
  37. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  38. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  39. 2026-09-11 01:23 UTCEG score recompute
  40. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  41. 2026-09-10 01:07 UTCEG score recompute
  42. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  43. 2026-09-08 21:17 UTCEG score recompute
  44. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  45. 2026-09-07 10:25 UTCEG score recompute
  46. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  47. 2026-09-06 07:03 UTCEG score recompute
  48. 2026-09-05 06:47 UTCEG score recompute
  49. 2026-09-04 06:08 UTCEG score recompute
  50. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  51. 2026-09-03 05:49 UTCEG score recompute
  52. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  53. 2026-09-02 04:59 UTCEG score recompute
  54. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  55. 2026-09-01 04:41 UTCEG score recompute
  56. 2026-08-31 04:24 UTCEG score recompute
  57. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  58. 2026-08-30 04:08 UTCEG score recompute
  59. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  60. 2026-08-29 03:52 UTCEG score recompute
  61. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  62. 2026-08-27 21:46 UTCEG score recompute
  63. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  64. 2026-08-26 21:31 UTCEG score recompute
  65. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  66. 2026-08-25 21:14 UTCEG score recompute
  67. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  68. 2026-08-24 20:59 UTCEG score recompute
  69. 2026-08-23 20:43 UTCEG score recompute
  70. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  71. 2026-08-22 20:28 UTCEG score recompute
  72. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  73. 2026-08-21 20:12 UTCEG score recompute
  74. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  75. 2026-08-19 19:40 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45129?
CVE-2026-45129 is a medium-severity vulnerability; its CVE record was published on August 18, 2026. MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP Recovery Codes module does not validate requests correctly, allowing same-site attackers to rotate a victim administrator's recovery codes with a specially crafted URL. The Admin CP Home, Preferences, Recovery Codes…
When was the CVE record for CVE-2026-45129 published?
The CVE record for CVE-2026-45129 was published on August 18, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 8, 2026; the record at its source may have been updated since.
Is CVE-2026-45129 actively exploited?
CVE-2026-45129 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45129?
CVE-2026-45129 has a CVSS base score of 4.6 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-45129?
A fix for CVE-2026-45129 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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