{"id":"CVE-2026-55786","title":"Flyto2 Core is an execution kernel for automation and AI-agent workflows","summary":"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 reg…","severity":"high","cvss":8.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-78","CWE-306"],"vendor":"flyto-core","product":"flyto-core","affected":["flyto-core >= 2.26.2, < 2.26.4"],"patched":["flyto-core 2.26.4"],"published":"2026-10-14","updated":"2026-10-16","sourceUpdated":"2026-10-16T20:04:29.760","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55786","references":[{"url":"https://github.com/flytohub/flyto-core/commit/db7f116b1d3c5dcf94aded00d14118f81f3e225e","label":"security-advisories@github.com"},{"url":"https://github.com/flytohub/flyto-core/releases/tag/v2.26.4","label":"security-advisories@github.com"},{"url":"https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85","label":"security-advisories@github.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55786"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/flyto-core/PYSEC-2026-2482.yaml"},{"url":"https://github.com/advisories/GHSA-h9f9-h6gm-wc85"},{"url":"https://github.com/flytohub/flyto-core"}],"tags":["nvd","ghsa","pip","cve.org","osv"],"epss":0.00256,"epssPercentile":0.17113,"aliases":["GHSA-h9f9-h6gm-wc85","PYSEC-2026-2482"],"ecosystem":"pip","ingestedAt":"2026-07-06T17:44:51.390Z","slug":"CVE-2026-55786","body":"## Overview\n\nFlyto2 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55786)\n\nAffected packages:\n\n- `flyto-core >= 2.26.2, < 2.26.4`\n\nPatched in:\n\n- `flyto-core 2.26.4`\n\nSource: https://github.com/advisories/GHSA-h9f9-h6gm-wc85","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":46.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}