Auth bypass in Rargames 4gaboards

CVE-2026-50191

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.

Vulnerability class: Broken Authentication

EPSS: 0.003 (25.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-50191?
CVE-2026-50191 is a high-severity vulnerability in Rargames 4gaboards, classified under Improper Authentication. CVSS score: 8.8/10. Published 2026-08-18.
How severe is CVE-2026-50191?
High severity. CVSS v3 base score is 8.8 out of 10.