# CVE-2026-53959: 4gaBoards: Mass Information Disclosure (Internal PII Leakage) on /api/users to any authenticated user

> Authenticated users can access sensitive personal information of all other users via unprotected API endpoints, enabling privacy loss and phishing.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-p77f-p47g-h72p

## What is CVE-2026-53959?

CVE-2026-53959 is a medium-severity vulnerability in RARgames 4gaBoards, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

4gaBoards is a boards system for realtime project management. Prior to 3.3.9, 4gaBoards allows any authenticated user to enumerate account information for every user through GET /api/users and retrieve arbitrary accounts through GET /api/users/:id. The users/index and users/show actions rely only on the default is-authenticated policy in server/config/policies.js, and server/api/controllers/users/index.js returns the result of sails.helpers.users.getMany() without requester-specific authorization or response sanitization. Responses expose email, phone, organization, name, isAdmin, ssoGoogleEmail, ssoGithubEmail, and other SSO-linked email fields, including data for administrators. This enables instance-wide user enumeration, privacy loss, and targeted phishing reconnaissance. This issue is fixed in version 3.3.9.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-53959?


## How do I fix CVE-2026-53959?

No fix has been published for CVE-2026-53959 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-53959 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53959 exists.

Public exploit code:

- 4gaBoards < 3.3.9 - User Information Disclosure (github_poc): https://github.com/anirbala98/CVE-2026-53959
- 4gaBoards Mass User Information Disclosure (CVE-2026-53959) (metasploit)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53959 and fix it if it is affected.

What it is: CVE-2026-53959 is a medium-severity vulnerability in RARgames 4gaBoards, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53959 exists.

Affected product: RARgames 4gaBoards. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53959/ (Markdown: https://insights.sbomify.com/CVE-2026-53959/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53959
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53959
- OSV: https://osv.dev/vulnerability/CVE-2026-53959

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53959/
Summaries are generated and may contain mistakes; the official description above is the record.