CVE-2026-39912

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-09. a secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unauthenticated attackers can POST to the loginWithMailLink endpoint with a known email address to receive the full authentication URL in the response, then exchange the token at the token2Login endpoint to obtain a valid bearer token with complete account access including admin privileges.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
72(Attend)
EG Risk 72/100SSVC: Attend

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
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

April 9, 2026

Last Modified

July 14, 2026

Advisory Details (8)

Auto-updated Sep 7, 2026
⚠️ Active exploitation confirmed. Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic

v2board / Xboard Authentication Token Exposure via loginWithMailLink | Advisories | VulnCheck

https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink
github_pr

Fix: CVE-2026-39912 - Magic link token leak in loginWithMailLink

Upstream fix in progress (PR #981 · v2board/v2board, state=open)

https://github.com/v2board/v2board/pull/981
generic

v2board/app/Http/Controllers/Passport/AuthController.php at 0ca47622a50116d0ddd7ffb316b157afb57d25e8 · v2board/v2board · GitHub

https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71
github_pr

Fix: CVE-2026-39912 - Magic link token leak in loginWithMailLink

Fix merged in cedar2025/Xboard PR #873 on 2026-04-09 — awaiting tagged release

https://github.com/cedar2025/Xboard/pull/873
github_commit

commit 121511523f04 (cedar2025/Xboard)

Fix landed in cedar2025/Xboard commit 121511523f04 — awaiting tagged release

https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957
generic

Xboard/app/Services/Auth/MailLinkService.php at 1fe6531924cc1ec662a88b9ef725afcf78d660bc · cedar2025/Xboard · GitHub

https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49
generic

Xboard/app/Http/Controllers/V1/Passport/AuthController.php at 1fe6531924cc1ec662a88b9ef725afcf78d660bc · cedar2025/Xboard · GitHub

https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51
generic🔴 Active Exploitation

Xboard / V2Board: Magic Link Token Leak - Unauthenticated Account Takeover - Chocapikk's Cybersecurity Blog

https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/

Weakness Classification(1)

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

Data Freshness Timeline

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCChocapikk/CVE-2026-39912
    First seen Apr 9, 2026

    Xboard / V2Board Unauth Account Takeover - Magic Link Token Leak (CVE-2026-39912)

    Open source ↗

Frequently asked(5)

What is CVE-2026-39912?
CVE-2026-39912 is a critical vulnerability published on April 9, 2026. V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the loginwithmaillinkenable feature is active. Unauthenticated attackers can POST to the loginWithMailLink endpoint with a known email address to receive…
When was CVE-2026-39912 disclosed?
CVE-2026-39912 was first published in the National Vulnerability Database on April 9, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39912 actively exploited?
CVE-2026-39912 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.9% of all scored CVEs.
What is the CVSS score of CVE-2026-39912?
CVE-2026-39912 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-39912?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39912, 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.

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