CVE-2026-50191: 4gaBoards: Pre-Account Takeover via SSO Email Linkage

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-18 · updated 2026-10-22
Weakness: CWE-287

Description

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.

Affected products

RARgames 4gaBoards: before 3.3.8

References

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