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Fencer Intel
high 8.8

CVE-2026-50191 json

4gaBoards: Pre-Account Takeover via SSO Email Linkage

published 5mo ago modified 20d ago also EUVD-2026-62201 , GHSA-f3p6-chc6-pc77

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository RARgames/4gaBoards. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

4gaBoards is a boards system for realtime project management. Prior to 3.3.8, 4gaBoards is vulnerable to pre-account takeover when registrationEnabled, localRegistrationEnabled, and ssoRegistrationEnabled are enabled and Google, GitHub, Microsoft, or OIDC SSO is configured. The POST /api/register endpoint permits creation of an unverified local account with a victim's email address, and POST /api/access-tokens permits that account to authenticate while isVerified is false. During the victim's first SSO login, server/api/helpers/users/get-create-one-for-github-sso.js, server/api/helpers/users/get-create-one-for-google-sso.js, server/api/helpers/users/get-create-one-for-microsoft-sso.js, and server/api/helpers/users/get-create-one-for-oidc-sso.js find the attacker-controlled account by email and link the verified SSO identity without confirming ownership of the local account. The attacker can retain local-password access to the linked account and obtain the victim's projects, data, and permissions. This issue is fixed in version 3.3.8.

Patch / fix

Is CVE-2026-50191 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • RARgames 4gaBoards

Classification

Weakness
  • CWE-287 Improper Authentication
  • CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of RARgames/4gaBoards published their own advisory on GitHub. Reviewed sources take precedence over it.