Vulnerability Description
Freeciv21 is a free open source, turn-based, empire-building strategy game. Versions prior to 3.1.1 crash with a stack overflow when receiving specially-crafted packets. A remote attacker can use this to take down any public server. A malicious server can use this to crash the game on the player's machine. Authentication is not needed and, by default, logs do not contain any useful information. All users should upgrade to Freeciv21 version 3.1.1. Running the server behind a firewall can help mitigate the issue for non-public servers. For local games, Freeciv21 restricts connections to the current user and is therefore not affected.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d
- https://github.com/longturn/freeciv21/releases/tag/v3.1.1
- https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3
- https://redmine.freeciv.org/issues/1955
FAQ
What is CVE-2026-33250?
CVE-2026-33250 is a vulnerability with a CVSS score of 7.5 (HIGH). Freeciv21 is a free open source, turn-based, empire-building strategy game. Versions prior to 3.1.1 crash with a stack overflow when receiving specially-crafted packets. A remote attacker can use this...
How severe is CVE-2026-33250?
CVE-2026-33250 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-33250?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.