{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-33250", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-18T02:42:27.509Z", "datePublished": "2026-03-23T23:38:02.070Z", "dateUpdated": "2026-03-24T13:36:23.980Z"}, "containers": {"cna": {"title": "Crash when receiving specially-crafted packets", "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "lang": "en", "description": "CWE-20: Improper Input Validation", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-121", "lang": "en", "description": "CWE-121: Stack-based Buffer Overflow", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3"}, {"name": "https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6", "tags": ["x_refsource_MISC"], "url": "https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6"}, {"name": "https://github.com/longturn/freeciv21/releases/tag/v3.1.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/longturn/freeciv21/releases/tag/v3.1.1"}, {"name": "https://redmine.freeciv.org/issues/1955", "tags": ["x_refsource_MISC"], "url": "https://redmine.freeciv.org/issues/1955"}], "affected": [{"vendor": "longturn", "product": "freeciv21", "versions": [{"version": "< 3.1.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-23T23:38:02.070Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-f76g-6w3f-f6r3", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-24T13:36:15.835264Z", "id": "CVE-2026-33250", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-24T13:36:23.980Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-33250", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-24T13:36:15.835264Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-24T13:36:18.996Z"}}], "cna": {"title": "Crash when receiving specially-crafted packets", "source": {"advisory": "GHSA-f76g-6w3f-f6r3", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "longturn", "product": "freeciv21", "versions": [{"status": "affected", "version": "< 3.1.1"}]}], "references": [{"url": "https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3", "name": "https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6", "name": "https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/longturn/freeciv21/releases/tag/v3.1.1", "name": "https://github.com/longturn/freeciv21/releases/tag/v3.1.1", "tags": ["x_refsource_MISC"]}, {"url": "https://redmine.freeciv.org/issues/1955", "name": "https://redmine.freeciv.org/issues/1955", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "CWE-20: Improper Input Validation"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-121", "description": "CWE-121: Stack-based Buffer Overflow"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-23T23:38:02.070Z"}}}, "cveMetadata": {"cveId": "CVE-2026-33250", "state": "PUBLISHED", "dateUpdated": "2026-03-24T13:36:23.980Z", "dateReserved": "2026-03-18T02:42:27.509Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-03-23T23:38:02.070Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "Freeciv21 es un juego de estrategia gratuito de c\u00f3digo abierto, por turnos, de construcci\u00f3n de imperios. Las versiones anteriores a la 3.1.1 fallan con un desbordamiento de pila al recibir paquetes especialmente dise\u00f1ados. Un atacante remoto puede usar esto para derribar cualquier servidor p\u00fablico. Un servidor malicioso puede usar esto para bloquear el juego en la m\u00e1quina del jugador. No se necesita autenticaci\u00f3n y, por defecto, los registros no contienen ninguna informaci\u00f3n \u00fatil. Todos los usuarios deber\u00edan actualizar a la versi\u00f3n 3.1.1 de Freeciv21. Ejecutar el servidor detr\u00e1s de un cortafuegos puede ayudar a mitigar el problema para servidores no p\u00fablicos. Para juegos locales, Freeciv21 restringe las conexiones al usuario actual y por lo tanto no se ve afectado."}], "id": "CVE-2026-33250", "lastModified": "2026-04-15T15:47:31.327", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-24T00:16:29.830", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/longturn/freeciv21/commit/ad8e18ca22595529599782b2984bf44df8d69ed6"}, {"source": "security-advisories@github.com", "url": "https://github.com/longturn/freeciv21/releases/tag/v3.1.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/longturn/freeciv21/security/advisories/GHSA-f76g-6w3f-f6r3"}, {"source": "security-advisories@github.com", "url": "https://redmine.freeciv.org/issues/1955"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-121"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.1.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "freeciv21", "source": "cna", "vendor": "longturn"}, "product": "freeciv21", "vendor": "longturn"}], "analysis": {"en": {"generated_at": "2026-03-24T03:40:00.791486+00:00", "value": {"mitigation_remediation": ["Upgrade Freeciv21 to version 3.1.1 or later.", "Configure a firewall to restrict access to the server if it is not intended to be publicly available.", "Verify that client installations are also at or above v3.1.1 to prevent crashes from malicious servers.", "Check log files to confirm no additional information is recorded post\u2011patch."], "summary": {"action": "Immediate Patch", "impact": "Denial of Service"}, "threat_synthesis": {"affected_systems": "The issue affects the Freeciv21 open\u2011source turn\u2011based strategy game, specifically any installation using a version earlier than 3.1.1. Public servers running this software are vulnerable; servers running only locally or restricted to the current user are not impacted.", "description_and_impact": "A stack overflow occurs when Freeciv21 processes specially\u2011crafted packets before version 3.1.1, causing the server or client to crash. An attacker can trigger this from any networked connection without authentication, leading to abrupt termination of the game or server. The vulnerability is classified as a buffer overread/call stack corruption.", "risk_and_exploitability": "The CVSS score of 7.5 signifies high severity, while no EPSS data is available and the vulnerability is not listed in the CISA KEV catalog. Because the flaw can be triggered remotely without authentication and relies on network packet manipulation, the likelihood of exploitation remains significant, especially for publicly exposed gaming servers."}}}}, "created": "2026-03-24T10:29:50.395719+00:00", "updated": "2026-03-25T20:35:57.649718+00:00", "vendors": ["longturn", "longturn$PRODUCT$freeciv21"]}