CVE-2026-33250
Publication date 26 March 2026
Last updated 26 March 2026
Ubuntu priority
Cvss 3 Severity Score
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| freeciv | 25.10 questing |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-33250
- https://redmine.freeciv.org/issues/1955
- https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6
- https://github.com/longturn/freeciv21/releases/tag/v3.1.1
- https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3