CVE-2026-55786
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-78 · OS command injection
- Record status
- Deferred
Attack profile CVSS 3.1 · 8.4
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Fix and advisories
- https://github.com/flytohub/flyto-core/commit/db7f116b1d3c5dcf94aded00d14118f81f3e225e
- https://github.com/flytohub/flyto-core/releases/tag/v2.26.4
- https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85
- https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85
References
- https://github.com/flytohub/flyto-core/commit/db7f116b1d3c5dcf94aded00d14118f81f3e225e
- https://github.com/flytohub/flyto-core/releases/tag/v2.26.4
- https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85
- https://github.com/flytohub/flyto-core/security/advisories/GHSA-h9f9-h6gm-wc85