What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-09-26 · updated 2026-10-09
• Weakness: CWE-359

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.

Affected products

• FlagForgeCTF flagForge: from 2.0 before 2.3.1 — fixed in 2.3.1

How to fix

Upgrade to a fixed version: FlagForgeCTF flagForge 2.3.1. Check the vendor advisory for mitigations.

References

• https://github.com/FlagForgeCTF/flagForge/commit/1b033f1b6e20fbf6df422d5d1afc9b2347528ace
• https://github.com/FlagForgeCTF/flagForge/compare/v2.3.1...v2.3.2
• https://github.com/FlagForgeCTF/flagForge/releases/tag/v2.3.1
• https://github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-qqjv-8r5p-7xpj

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