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.
CVE-2026-39912
“—” beside the score: it is equal to the CVSS score beside it.
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.
Also known asEUVD-2026-21043 (ENISA EUVD) · GHSA-83h9-46h8-whf4 (GitHub Security Advisories)Source: ENISA EUVD
- Public exploit or proof-of-concept code is available
An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.
- CVSS v3
- 9.1
- EG Score
- 9.1CRITICALmedium confidence
- EG Risk
- 72EG Risk 72/100
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)Severity91% × 45%Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release. - EPSS PROB
- 0.6%
- EPSS %ILE
- 48th
- 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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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 low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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 low, Track* at medium and Attend at high mission impact.
An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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
April 9, 2026
Last Modified
October 26, 2026
Advisory Details (8)
Auto-updated Sep 16, 2026v2board / Xboard Authentication Token Exposure via loginWithMailLink | Advisories | VulnCheck
https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillinkFix: 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/981v2board/app/Http/Controllers/Passport/AuthController.php at 0ca47622a50116d0ddd7ffb316b157afb57d25e8 · v2board/v2board · GitHub
https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71Fix: 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/873commit 121511523f04 (cedar2025/Xboard)
Fix landed in cedar2025/Xboard commit 121511523f04 — awaiting tagged release
https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957Xboard/app/Services/Auth/MailLinkService.php at 1fe6531924cc1ec662a88b9ef725afcf78d660bc · cedar2025/Xboard · GitHub
https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49Xboard/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#L51Xboard / 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 23× in last 7d / 71× 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 99 of 299 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 200 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-30 19:00 UTCEG score recompute
- 2026-10-30 19:00 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-29 17:00 UTCEG score recompute
- 2026-10-29 17:00 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-28 14:59 UTCEG score recompute
- 2026-10-28 14:59 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-27 12:52 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-26 21:27 UTCEG score recompute
- 2026-10-26 21:27 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-26 02:53 UTCEG score recompute
- 2026-10-26 02:53 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-25 14:31 UTCEG score recompute
- 2026-10-25 00:51 UTCEG score recompute
- 2026-10-25 00:51 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-23 22:51 UTCEG score recompute
- 2026-10-23 22:51 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-22 20:43 UTCEG score recompute
Show 74 moreShow fewer
- 2026-10-22 20:43 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-21 18:39 UTCEG score recompute
- 2026-10-21 18:39 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-20 16:39 UTCEG score recompute
- 2026-10-20 16:39 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-19 14:38 UTCEG score recompute
- 2026-10-19 14:37 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-18 12:37 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-18 03:43 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-17 10:35 UTCEG score recompute
- 2026-10-17 10:35 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-16 08:35 UTCEG score recompute
- 2026-10-16 08:35 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-15 06:33 UTCEG score recompute
- 2026-10-15 06:33 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-14 02:13 UTCEG score recompute
- 2026-10-14 02:13 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-12 22:32 UTCEG score recompute
- 2026-10-12 22:32 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-12 16:10 UTCEG score recompute
- 2026-10-12 08:08 UTCGHSA enrichmentGHSA-83h9-46h8-whf4 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-11 19:52 UTCEG score recompute
- 2026-10-11 17:05 UTCEG score recompute
- 2026-10-11 14:32 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-11 09:44 UTCOSV refresh
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-21 22:15 UTCOSV refresh
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 46th percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-02 18:08 UTCOSV refresh
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.6% · 45th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.6% · 45th percentile
Publicly available exploits
(1 reference)Public exploit code is referenced for this CVE (1 GitHub PoC). The fix is not yet in a release, so defenders should restrict or isolate affected systems accordingly until it ships.
- GitHub PoCChocapikk/CVE-2026-39912Published Apr 9, 2026
Xboard / V2Board Unauth Account Takeover - Magic Link Token Leak (CVE-2026-39912)
Open source ↗
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-39912?
When was the CVE record for CVE-2026-39912 published?
Is CVE-2026-39912 actively exploited?
What is the CVSS score of CVE-2026-39912?
How do I remediate CVE-2026-39912?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-39912
Is Your Infrastructure Affected by CVE-2026-39912?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.