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FlowiseApplication · Flowiseai

CVE-2026-56274

CRITICAL · 9.9 CVSS v3.1 Published 2026-06-23
Fix available
A fix is available. Upgrade to 3.1.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature. The validateCommandFlags blocklist is incomplete, allowing bypasses like 'docker build' and 'npx --yes', and validateArgsForLocalFileAccess checks can be evaded via regex bypass, enabling arbitrary command execution on the host.

MitigationUpgrade to Flowise 3.1.2 or later to patch the command injection vulnerabilities. Until patched, restrict or disable the Custom MCP Server feature and monitor for unauthorized chatflow configurations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FlowiseApplication
Affected:< 3.1.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Flowise version
    Check the package.json file in the Flowise installation directory for the version field, or run 'npm list flowise' if npm is available
    Affected if The version is below 3.1.2
  2. Locate the Flowise installation directory
    Common locations include /opt/flowise, /home/*/flowise, or the directory where Flowise was deployed; check process running the service for the path
    Affected if Unable to determine installation path or version
  3. Determine if Custom MCP Server feature is accessible
    Log into Flowise as a user with chatflow access and navigate to the chatflow editor to see if there is an option to add a Custom MCP Server or Custom Tool
    Affected if The Custom MCP Server feature is visible and configurable to the user
  4. Check existing MCP server configurations
    Review any configured MCP servers in chatflows by examining the chatflow configuration files or database entries for MCP server definitions
    Affected if Any MCP server configurations exist that may include shell commands or external tool references

A user is affected if Flowise version is below 3.1.2 AND they have access to chatflows where the Custom MCP Server feature can be configured.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.1.2 or later
Fixed in 3.1.2
Interim mitigation

Upgrade to Flowise 3.1.2 or later to patch the command injection vulnerabilities. Until patched, restrict or disable the Custom MCP Server feature and monitor for unauthorized chatflow configurations.

Recommended fix Moderate confidence

Flowise 3.1.2

  1. 1. Back up your current Flowise configuration and data
  2. 2. Upgrade Flowise to version 3.1.2 or later by running: npm install flowise@latest or your preferred package manager update command
  3. 3. Verify the upgrade completed successfully
  4. 4. Review user permissions and API access for chatflows to ensure only necessary personnel have view/update permissions
  5. 5. Monitor for any suspicious activity or unauthorized command execution
Caveat Review release notes for any breaking changes between your current version and 3.1.2

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Flowise Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,330
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-56274 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data