Critical 9.9Published Jun 23, 2026

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

Updated under an hour ago (Oct 26, 2026, 11:50 PM ET)

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It affects Flowise and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Flowise

Exploited in the last 30 days

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: 9.9 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-78
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Analyzed
Record last updated: Jun 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Flowise Flowise flowise:flowise (from the name)	before 3.1.2; 3.1.2 not affected	CNA record
Flowise Flowise Components flowise:components (from the name)	before 3.1.2; 3.1.2 not affected	CNA record
flowiseai flowise flowiseai:flowise	before 3.1.2	NVD

References

References

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q	vendor-advisory, exploit, third-party-advisory
https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.