{"id":"CVE-2026-47427","sourceIdentifier":"security-advisories@github.com","published":"2026-07-28T16:18:14.853","lastModified":"2026-10-24T13:10:00.147","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go runtime panic; because the crash occurs before any authentication or token validation, any unauthenticated client able to send JSON-RPC messages can crash the server, resulting in a complete denial of service. This issue is fixed in version 1.1.0."},{"lang":"es","value":"El Servidor MCP de GitHub es el Servidor MCP oficial de GitHub. Antes de la 1.1.0, la función CompletionsHandler en pkg/github/server.go accede a params.Ref sin verificar primero si es nulo, por lo que una solicitud de completion/complete con un campo ref faltante o vacío desencadena una desreferenciación de puntero nulo y un pánico en tiempo de ejecución de Go; debido a que el fallo ocurre antes de cualquier autenticación o validación de token, cualquier cliente no autenticado capaz de enviar mensajes JSON-RPC puede hacer que el servidor falle, resultando en una denegación de servicio completa. Este problema está solucionado en la versión 1.1.0."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"github","product":"github-mcp-server","versions":[{"version":"< 1.1.0","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-28T17:31:12.371732Z","id":"CVE-2026-47427","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-476"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:github:mcp_server:*:*:*:*:*:*:*:*","versionEndExcluding":"1.1.0","matchCriteriaId":"FEBF9CB4-D9DD-4A31-B17E-F5B42B16AEE1"}]}]}],"references":[{"url":"https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/github/github-mcp-server/pull/2502","source":"security-advisories@github.com","tags":["Issue Tracking","Patch"]},{"url":"https://github.com/github/github-mcp-server/releases/tag/v1.1.0","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Vendor Advisory"]}]}