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: 0.4%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

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 15× in last 7d / 84× 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 217 total refreshes for this CVE.

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

Related CVEs(same CWE)

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 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 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-39923?
CVE-2026-39923 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-39923?
A fix for CVE-2026-39923 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-39923 are linked in the Vendor Advisories panel on this page.

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