dbcve.org
FlowiseApplication · Flowiseai

CVE-2025-8943

CRITICAL · 9.8 CVSS v3.1 Published 2025-08-14
Fix available
A fix is available. Upgrade to 3.0.1 or later.
See remediation →
100/100
Remediation priority · Urgent
High EPSS Public exploit Remotely reachable No privileges 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
The Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers. However, Flowise's inherent authentication and authorization model is minimal and lacks role-based access controls (RBAC). Furthermore, in Flowise versions before 3.0.1 the default installation operates without authentication unless explicitly configured. This combination allows unauthenticated network attackers to execute unsandboxed OS commands.

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's Custom MCPs feature allows OS command execution (e.g., via npx) but lacks proper access controls. Combined with the default installation operating without authentication in versions before 3.0.1 and the absence of role-based access controls (RBAC), unauthenticated remote attackers can execute arbitrary OS commands on the host system.

MitigationUpgrade to Flowise 3.0.1 or later and explicitly enable/configure authentication to prevent unauthenticated access; network segmentation provides additional defense-in-depth.

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:< 3.0.1

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 Flowise installation and version
    Locate the Flowise installation (e.g., check running processes, Docker containers, or npm packages). Run 'flowise version' or check package.json for the installed Flowise version.
    Affected if The installed version is below 3.0.1 (e.g., 3.0.0, 2.x.x, 1.x.x)
  2. Verify if authentication is enabled
    Check Flowise configuration files (e.g., .env file or config.yaml) for AUTH_ENABLED=true or similar authentication settings. Also check the Flowise admin UI under Settings to see if authentication is turned on.
    Affected if Authentication is disabled or not explicitly configured (the default state in versions before 3.0.1)
  3. Confirm Custom MCPs feature accessibility
    Check if the /api/v1/mcp or similar MCP-related endpoints are accessible without authentication. Review Flowise server logs or configuration for MCP-related routes and whether they require authentication.
    Affected if Custom MCPs endpoints are accessible to unauthenticated users (no auth required to access the feature)
  4. Assess network exposure
    Determine if the Flowise server is directly exposed to the internet or accessible on untrusted networks. Check firewall rules, reverse proxy configurations, and binding addresses (e.g., if bound to 0.0.0.0 vs localhost).
    Affected if Flowise is accessible from untrusted networks without network segmentation or VPN protection

If Flowise version is below 3.0.1 AND authentication is not enabled AND the Custom MCPs feature is network-accessible to unauthenticated users, the environment is affected by this vulnerability.

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 3.0.1 or later
Fixed in 3.0.1
Interim mitigation

Upgrade to Flowise 3.0.1 or later and explicitly enable/configure authentication to prevent unauthenticated access; network segmentation provides additional defense-in-depth.

Recommended fix High confidence

Flowise 3.0.1 or later

  1. 1. Back up your current Flowise installation and configuration
  2. 2. Upgrade Flowise to version 3.0.1 or later
  3. 3. After upgrading, explicitly configure authentication in your Flowise installation
  4. 4. Verify that authentication is enforced by attempting to access the Flowise interface without credentials
  5. 5. Ensure the Custom MCPs feature is only accessible to authenticated users
Caveat After upgrading, you must explicitly enable and configure authentication; the default no-auth behavior is changed

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

Fix this in Flowise Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.

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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-2025-8943 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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