# CVE-2025-59843: FlagForgeCTF Exposes User Emails via Public /api/user/[username] API

> Attackers can retrieve user email addresses via a public API endpoint, exposing private user data.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Sep 2025
- **Updated:** 28 Jan 2026
- **Also known as:** GHSA-qqjv-8r5p-7xpj

## What is CVE-2025-59843?

CVE-2025-59843 is a medium-severity vulnerability in FlagForgeCTF flagForge, published on 26 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Flag Forge is a Capture The Flag (CTF) platform. From versions 2.0.0 to before 2.3.2, the public endpoint /api/user/[username] returns user email addresses in its JSON response. The fix, intended for release in 2.3.1 but only available starting in version 2.3.2, removes email addresses from public API responses while keeping the endpoint publicly accessible. Users should upgrade to version 2.3.2 or later to eliminate exposure. There are no workarounds for this vulnerability.

Weakness: CWE-359 (Exposure of Private Personal Information to an Unauthorized Actor)

## Which versions are affected by CVE-2025-59843?

It affects 1 product.


Products: Flagforge Flagforge.

## How do I fix CVE-2025-59843?

No fix has been published for CVE-2025-59843 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-59843 being exploited?

There is no known exploitation of CVE-2025-59843 in the wild and no public exploit code.

Public exploit code:

- CVE on FlagForge on versions 2.0.0 to 2.3.0. Upgrade to version 2.3.1 to fix the issue. (github_poc): https://github.com/At0mXploit/CVE-2025-59843-CVE-2025-59932

## Other vulnerabilities in FlagForgeCTF flagForge

- [CVE-2025-59841](https://insights.sbomify.com/CVE-2025-59841/): FlagForgeCTF's Improper Session Handling Allows Access After Logout (critical 9.8)
- [CVE-2025-61777](https://insights.sbomify.com/CVE-2025-61777/): FlagForge Allows Unauthenticated Badge Template API Access (critical 9.4)
- [CVE-2025-59932](https://insights.sbomify.com/CVE-2025-59932/): FlagForgeCTF Unauthenticated Resource Modification/Deletion (high 8.6)
- [CVE-2025-59827](https://insights.sbomify.com/CVE-2025-59827/): FlagForgeCTF is Missing Authorization in main-v2 (high 8.2)
- [CVE-2025-59826](https://insights.sbomify.com/CVE-2025-59826/): FlagForgeCTF Vulnerable to Unauthorized Problem Creation (high 7.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-59843 and fix it if it is affected.

What it is: CVE-2025-59843 is a medium-severity vulnerability in FlagForgeCTF flagForge, published on 26 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-59843 in the wild and no public exploit code.

Affected product: FlagForgeCTF flagForge. 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-2025-59843/ (Markdown: https://insights.sbomify.com/CVE-2025-59843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-59843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-59843
- OSV: https://osv.dev/vulnerability/CVE-2025-59843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-59843/
Summaries are generated and may contain mistakes; the official description above is the record.