{"id":"CVE-2026-55786","summary":"Flyto2 Core: Unauthenticated Command Execution via HTTP MCP `execute_module`","details":"Flyto2 Core is an execution kernel for automation and AI-agent workflows. From 2.26.2 until 2.26.4, the HTTP MCP POST /mcp route accepts unauthenticated JSON-RPC tools/call requests and forwards execute_module arguments to the module registry without the require_auth dependency used by the REST execution routes. An unauthenticated caller can select sandbox.execute_shell and supply its command parameter, which reaches asyncio.create_subprocess_shell with the privileges of the flyto-core server process. The endpoint is reachable locally under the default loopback binding and becomes network reachable when an operator binds the server to a non-loopback interface, allowing arbitrary OS command execution and potential full host compromise. This issue is fixed in version 2.26.4.","aliases":["GHSA-h9f9-h6gm-wc85","PYSEC-2026-2482"],"modified":"2026-10-16T02:48:01.878481976Z","published":"2026-10-14T18:14:39.210Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-306","CWE-78"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55786.json"},"references":[{"type":"WEB","url":"https://github.com/flytohub/flyto-core/releases/tag/v2.26.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55786.json"},{"type":"ADVISORY","url":"https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55786"},{"type":"FIX","url":"https://github.com/flytohub/flyto-core/commit/db7f116b1d3c5dcf94aded00d14118f81f3e225e"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/flytohub/flyto-core","events":[{"introduced":"0"},{"fixed":"db7f116b1d3c5dcf94aded00d14118f81f3e225e"},{"fixed":"50d0d327a1278c8cec9495ba5f6f010dd67ef19c"}],"database_specific":{"extracted_events":[{"introduced":"2.26.2"},{"fixed":"2.26.4"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v2.26.3","v2.26.0","v2.25.27","v2.17.6","v2.16.3","v2.5.0","v2.2.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55786.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}