{"id":"CVE-2026-108714","summary":"MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocket","details":"MCP Kotlin SDK through 0.15.0 contains an uncontrolled memory allocation vulnerability that allows remote clients to exhaust server memory because Application.mcpWebSocket installs Ktor WebSockets without a maxFrameSize limit. Attackers can send small frame headers declaring payloads near 2 GiB over one or a few connections, forcing huge heap allocations and causing denial of service.","modified":"2026-10-13T02:45:33.570461450Z","published":"2026-10-11T12:19:27.291Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/108xxx/CVE-2026-108714.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/108xxx/CVE-2026-108714.json"},{"type":"ADVISORY","url":"https://hackmd.io/@haind/mcp-kotlin-sdk-websocket-frame-allocation-dos"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-108714"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/mcp-kotlin-sdk-through-0.15.0-memory-exhaustion-via-application-mcpwebsocket"},{"type":"PACKAGE","url":"https://github.com/modelcontextprotocol/kotlin-sdk"},{"type":"ARTICLE","url":"https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/WebSocketMcpTransport.kt#L60-L85"},{"type":"ARTICLE","url":"https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/WebSocketMcpKtorServerExtensions.kt#L41-L63"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/modelcontextprotocol/kotlin-sdk","events":[{"introduced":"0"},{"fixed":"76b8e7d63aac39fe41e03684e3b91a6c3724a8da"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"0.15.0"},{"fixed":"0.15.0"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["0.14.0","0.13.0","0.12.0","0.11.1","0.11.0","0.9.0","0.8.3","0.8.1","0.8.0","0.7.7","0.7.6","0.7.5","0.7.4","0.7.2","0.7.2-alpha3","0.7.2-alpha2","0.7.2-alpha1","0.7.1","v0.7.0","0.7.0","0.6.0","0.5.0","0.4.0","0.3.0","0.2.0","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-108714.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}