Vulnerability · Published Aug 18, 2026 · Assigned by GitHub_M
CVE-2026-539584gaBoards: SSO Pre-Account Takeover / Hijacking via Mass Assignment
High 7.6
In plain English
A high-severity improper authentication in 4gaBoards from RARgames. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Official description
4gaBoards is a boards system for realtime project management. Prior to 3.3.9, 4gaBoards allows an authenticated user to modify ssoGoogleId, ssoGoogleEmail, ssoGithubId, ssoGithubUsername, ssoGithubEmail, ssoMicrosoftId, ssoMicrosoftEmail, ssoOidcId, and ssoOidcEmail through PATCH /api/users/:id. The whitelist in server/api/controllers/users/update.js mass assigns these backend-managed identity attributes from user input. An attacker can place a victim's provider identifier on an attacker-controlled account, causing the default lookup in helpers such as server/api/helpers/users/get-create-one-for-github-sso.js to match the victim's first SSO login to the attacker's account before the email-linkage flow runs. The victim is logged into the attacker-controlled account, and projects, boards, or data the victim creates remain accessible through the attacker's original local credentials. This issue is fixed in version 3.3.9.
Affected products (as reported)
Weakness: CWE-287, CWE-915 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L