CVE-2026-56274highCWE-78

CVE-2026-56274: high-severity vulnerability in Flowise

Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess

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36Vexday Risk Score

Patch soon. It has a working public exploit.

ssvc Attendcvss 8.7epss 7.5%
from disclosure to weaponsame day
Published on NVDJun 23
metasploitJun 23
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
Flowise · FlowiseFlowise · Flowise Components
Related CVEs — Flowise

In the same product, most dangerous first.

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