cvedb.io
CVE-2026-56274
CRITICAL · CVSS 9.9
EPSS exploitation probability: 74%
Published 2026-06-23T13:16:45.083 · Last modified 2026-06-24T13:16:35.810

Summary

Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.