CVE-2026-39923

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-05. the CNA's CVSS baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
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(high)
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

August 14, 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 29× in last 7d / 68× 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. 2026-08-21 06:31 UTCEG score recompute
  2. 2026-08-21 06:31 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 18:38 UTCGHSA enrichment
  5. 2026-08-20 06:45 UTCGHSA enrichment
  6. 2026-08-19 18:52 UTCEG score recompute
  7. 2026-08-19 18:52 UTCGHSA enrichment
  8. 2026-08-19 17:03 UTCEPSS rescore
  9. 2026-08-19 06:24 UTCGHSA enrichment
  10. 2026-08-18 18:14 UTCEG score recompute
  11. 2026-08-18 18:14 UTCGHSA enrichment
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-18 04:25 UTCGHSA enrichment
  14. 2026-08-17 16:32 UTCEG score recompute
  15. 2026-08-17 16:32 UTCGHSA enrichment
  16. 2026-08-17 13:47 UTCEPSS rescore
  17. 2026-08-17 04:35 UTCGHSA enrichment
  18. 2026-08-16 16:42 UTCEG score recompute
  19. 2026-08-16 16:42 UTCGHSA enrichment
  20. 2026-08-16 14:56 UTCEPSS rescore
  21. 2026-08-16 04:50 UTCEG score recompute
  22. 2026-08-16 04:50 UTCGHSA enrichment
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 16:57 UTCGHSA enrichment
  25. 2026-08-15 05:04 UTCEG score recompute
Show 43 more
  1. 2026-08-15 05:04 UTCGHSA enrichment
  2. 2026-08-15 01:30 UTCEPSS rescore
  3. 2026-08-14 17:11 UTCEG score recompute
  4. 2026-08-14 17:11 UTCGHSA enrichment
  5. 2026-08-14 06:31 UTCEG score recompute
  6. 2026-08-14 06:31 UTCGHSA enrichment
  7. 2026-08-13 22:00 UTCEPSS rescore
  8. 2026-08-13 18:38 UTCGHSA enrichment
  9. 2026-08-13 06:46 UTCGHSA enrichment
  10. 2026-08-12 18:53 UTCEG score recompute
  11. 2026-08-12 18:53 UTCGHSA enrichment
  12. 2026-08-12 13:51 UTCEPSS rescore
  13. 2026-08-12 07:00 UTCGHSA enrichment
  14. 2026-08-11 19:07 UTCEG score recompute
  15. 2026-08-11 19:07 UTCGHSA enrichment
  16. 2026-08-11 13:43 UTCEPSS rescore
  17. 2026-08-11 07:14 UTCEG score recompute
  18. 2026-08-11 07:14 UTCGHSA enrichment
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 19:22 UTCGHSA enrichment
  21. 2026-08-10 07:29 UTCGHSA enrichment
  22. 2026-08-09 19:36 UTCEG score recompute
  23. 2026-08-09 19:36 UTCGHSA enrichment
  24. 2026-08-09 13:46 UTCEPSS rescore
  25. 2026-08-09 07:44 UTCGHSA enrichment
  26. 2026-08-08 19:51 UTCEG score recompute
  27. 2026-08-08 19:51 UTCGHSA enrichment
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-08 07:58 UTCGHSA enrichment
  30. 2026-08-07 20:05 UTCEG score recompute
  31. 2026-08-07 20:05 UTCGHSA enrichment
  32. 2026-08-07 08:12 UTCGHSA enrichment
  33. 2026-08-06 20:19 UTCEG score recompute
  34. 2026-08-06 20:19 UTCGHSA enrichment
  35. 2026-08-06 13:46 UTCEPSS rescore
  36. 2026-08-06 08:26 UTCGHSA enrichment
  37. 2026-08-05 20:33 UTCEG score recompute
  38. 2026-08-05 20:33 UTCGHSA enrichment
  39. 2026-08-05 20:15 UTCEG score recompute
  40. 2026-08-05 20:15 UTCGHSA enrichment
  41. 2026-08-05 16:29 UTCEG score recompute
  42. 2026-08-05 15:26 UTCEG score recompute
  43. 2026-08-05 15:25 UTCMITRE cvelistV5first tracked

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 August 14, 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 82.0% of all scored CVEs.
What is the CVSS score of CVE-2026-39923?
CVE-2026-39923 has a CVSS v4.0 base score of 8.1 (CNA self-assessment; NVD's own analysis pending).
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

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