CVE-2026-39923

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-05. a secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 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.

Flarum before 1.8.16 contains a password reset token expiry bypass vulnerability that allows unauthenticated attackers to reuse expired password reset tokens by submitting them directly to the reset processing endpoint. The SavePasswordController::handle() method calls PasswordToken::findOrFail() without performing any expiry validation, allowing attackers to bypass the 24-hour token lifetime enforced only during form rendering and change any account's password to gain an authenticated session.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

August 5, 2026

Last Modified

September 9, 2026

Advisory Details (4)

Auto-updated Aug 5, 2026
Patch available. Sources: github_release, github_pr, github_commit.
generic

Flarum < 1.8.16 Password Reset Token Expiry Bypass via POST /reset | Advisories | VulnCheck

https://www.vulncheck.com/advisories/flarum-password-reset-token-expiry-bypass-via-post-reset
github_commit Patch Available

commit 2803058d0f9d (flarum/framework)

Patch available: flarum/framework v1.8.16 (contains commit 2803058d0f9d)

https://github.com/flarum/framework/commit/2803058d0f9dc38252326070b46d4484fe5a857d
github_pr Patch Available

[1.x] fix: enforce expiry check on password reset token submission

Patch available: flarum/framework v1.8.16 (PR #4545 merged 2026-04-11)

https://github.com/flarum/framework/pull/4545
github_release Patch Available

v1.8.16

Patch available: flarum/framework v1.8.16

https://github.com/flarum/framework/releases/tag/v1.8.16

Vendor Advisories for CVE-2026-39923(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 25× in last 7d / 104× 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.

Showing the most recent 100 of 168 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-39923?
CVE-2026-39923 is a high vulnerability published on August 5, 2026. Flarum before 1.8.16 contains a password reset token expiry bypass vulnerability that allows unauthenticated attackers to reuse expired password reset tokens by submitting them directly to the reset processing endpoint. The SavePasswordController::handle() method calls PasswordToken::findOrFail()…
When was CVE-2026-39923 disclosed?
CVE-2026-39923 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39923 actively exploited?
CVE-2026-39923 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 81.8% of all scored CVEs.
What is the CVSS score of CVE-2026-39923?
CVE-2026-39923 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-39923?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39923, 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

Explore the affected products and dependency analysis for CVE-2026-39923

Explore →

Is Your Infrastructure Affected by CVE-2026-39923?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs