dbcve.org
Information ExposureWeakness · CWE-200

CVE-2025-59434

CRITICAL · 9.6 CVSS v3.1 Published 2025-09-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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 is a drag & drop user interface to build a customized large language model flow. Prior to August 2025 Cloud-Hosted Flowise, an authenticated vulnerability in Flowise Cloud allows any user on the free tier to access sensitive environment variables from other tenants via the Custom JavaScript Function node. This includes secrets such as OpenAI API keys, AWS credentials, Supabase tokens, and Google Cloud secrets — resulting in a full cross-tenant data exposure. This issue has been patched in the August 2025 Cloud-Hosted Flowise.

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 Cloud prior to August 2025 had a tenant isolation failure in the Custom JavaScript Function node. Authenticated free-tier users could access environment variables (API keys, credentials, secrets) belonging to other tenants due to insufficient access controls, resulting in cross-tenant data exposure of sensitive credentials.

MitigationEnsure Flowise Cloud instances are updated to the August 2025 patch or later. For self-hosted deployments, verify that multi-tenant configurations properly isolate environment variables per tenant.

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

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
None

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

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. Check Flowise version
    Access the Flowise admin panel or check the running container/image tag. Compare the version number to the August 2025 release. For self-hosted, check package.json or the running Docker image tag.
    Affected if The installed version is prior to the August 2025 patch or the version cannot be verified.
  2. Verify multi-tenant configuration
    For self-hosted deployments, examine the configuration file (typically config/default.json or environment variables) for tenant isolation settings. Look for multi_tenant or TENANT isolation-related configuration keys.
    Affected if Multi-tenant mode is enabled but tenant isolation for environment variables is not properly configured.
  3. Identify use of Custom JavaScript Function node
    Review deployed flows in the Flowise instance. Search for any flows containing the Custom JavaScript Function node (often labeled as 'Custom JS' or 'JavaScript Function').
    Affected if The Custom JavaScript Function node is actively used in any deployed flow.
  4. Inspect environment variable exposure
    As an authenticated free-tier user, attempt to access the Custom JavaScript Function node configuration in a flow. Check if process.env or similar environment variable references can retrieve values belonging to other tenants.
    Affected if Environment variables from other tenants are accessible or visible in the node configuration.

A Flowise Cloud instance is affected if it is running a version prior to August 2025, has multi-tenant mode enabled, and has the Custom JavaScript Function node deployed, allowing cross-tenant access to environment variables.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Ensure Flowise Cloud instances are updated to the August 2025 patch or later. For self-hosted deployments, verify that multi-tenant configurations properly isolate environment variables per tenant.

Recommended fix High confidence

August 2025 Cloud-Hosted Flowise

  1. This is a vulnerability in Flowise Cloud (the SaaS offering), not self-hosted Flowise installations.
  2. Users of Flowise Cloud do not need to take any action - the vulnerability was patched by the vendor in the August 2025 release.
  3. If you are running a self-hosted instance of Flowise, this specific vulnerability does not affect you as it is exclusive to the Cloud-Hosted Flowise service.
  4. For assurance, verify with Flowise that your cloud account is on the August 2025 or later release.

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

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Testing8.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,360
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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-2025-59434 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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