CVE-2025-59841: Flagforge

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Flag Forge is a Capture The Flag (CTF) platform. In versions from 2.2.0 to before 2.3.1, the FlagForge web application improperly handles session invalidation. Authenticated users can continue to access protected endpoints, such as /api/profile, even after logging out. CSRF tokens are also still valid post-logout, which can allow unauthorized actions. This issue has been patched in version 2.3.1.

Affected products

• Flagforge Flagforge: from 2.2, before 2.3.1 (fixed in 2.3.1)

Published 2025-09-25. Last modified 2026-06-17.