CVE-2026-56274Public exploitNetwork attack vector

Authenticated command execution via MCP validation bypasses

Published Jun 23, 2026 · Updated Jun 23, 2026

OS command injection in Flowise before 3.1.2 allows remote authenticated users to execute arbitrary commands through Custom MCP configurations. The validateCommandFlags blocklist omits docker build and the npx --yes alias, while validateArgsForLocalFileAccess accepts double-slash absolute paths. Any Flowise account role, or an API key with chatflow view and update permissions, can trigger host command execution when a permitted runtime is installed.

CVSS severity8.7
High
EPSS probability7.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Flowise before 3.1.2 allows remote authenticated users to execute arbitrary commands through Custom MCP configurations. The validateCommandFlags blocklist omits docker build and the npx --yes alias, while validateArgsForLocalFileAccess accepts double-slash absolute paths. Any Flowise account role, or an API key with chatflow view and update permissions, can trigger host command execution when a permitted runtime is installed.

The record

CVE
CVE-2026-56274
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
FlowiseAI
Product
Flowise
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FlowiseAI · Flowiseversion=0 <3.1.2

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.9VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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