Vulnerability · Published Sep 25, 2025 · Assigned by GitHub_M

CVE-2025-59841FlagForgeCTF's Improper Session Handling Allows Access After Logout

Critical 9.8

In plain English

A critical-severity session fixation in flagForge from FlagForgeCTF. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.4%top 66.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
FlagForgeCTF	flagForge	>= 2.2.0, < 2.3.1

Weakness: CWE-384, CWE-613 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-h6pr-4cwv-6cjg x_refsource_CONFIRM
https://github.com/FlagForgeCTF/flagForge/commit/304b6c82a4f76871b336404b91e5cdd8a7d7d5bd x_refsource_MISC