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Vulnerabilities

Vulnerability · CVE-2026-33250

Freeciv21 is a free open source, turn-based, empire-building strategy game.

Published Mar 24, 2026 · catalog updated Jun 17, 2026 · Freeciv21 is a free

Check if you run it

No confirmed exploitation is on record for CVE-2026-33250. EPSS is 1.22%. Act only if a listed version of Freeciv21 is a free is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Freeciv21 is a free).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.22%
Remediation
Advisory link
Affected products
See sources for product scope

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.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-33250

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-33250. EPSS is 1.22%. Act only if a listed version of Freeciv21 is a free is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-121: Stack-based Buffer Overflow; CWE-20: Improper Input Validation. EPSS 1.22%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 24, 2026 · NIST NVD

    Detected

    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. Al

  2. Jun 17, 2026 · NIST NVD

    Updated

    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. Al

Sources

  • CVE.orgVulnerability recordCVE-2026-33250

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-33250

    30-day exploitation probability 1.2%

    first.org
  • NIST NVDVulnerability recordCVE-2026-33250

    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 ga

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.