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FlowiseApplication · Flowiseai

CVE-2026-56277

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-30
Fix available
A fix is available. Upgrade to 3.1.2 or later.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click 7 weeks old

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 sets Access-Control-Allow-Origin to a hardcoded wildcard (*) on its text-to-speech (TTS) generation endpoint (packages/server/src/controllers/text-to-speech/index.ts), independent of the server's configured CORS policy. This bypasses the server's otherwise restrictive default CORS configuration (getCorsOptions()) and allows any webpage to make cross-origin requests that trigger TTS generation using stored credentials, enabling drive-by cross-origin credential abuse.

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 a CORS misconfiguration where the text-to-speech generation endpoint hardcodes Access-Control-Allow-Origin to '*' (wildcard), bypassing the server's otherwise restrictive default CORS policy. This allows any origin to send authenticated cross-origin requests to the TTS endpoint, enabling drive-by credential abuse where malicious webpages can trigger TTS generation using the victim's stored credentials.

MitigationUpgrade to Flowise version 3.1.2 or later, which corrects the TTS endpoint to respect the server's configured CORS policy via getCorsOptions() instead of using a hardcoded wildcard.

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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. Identify Flowise installation and version
    Locate the Flowise installation and determine the installed version by checking package.json, docker image tag, or the /api/v1/health endpoint response
    Affected if The installed version is any release before 3.1.2
  2. Verify if TTS feature is enabled
    Check if text-to-speech capabilities are configured in the Flowise instance by examining the deployed configurations, environment variables, or available nodes in the Flowise UI
    Affected if Text-to-speech functionality is enabled and accessible in the environment
  3. Inspect CORS headers on the TTS endpoint
    Send an OPTIONS request to the TTS generation endpoint (typically /api/v1/tts or similar path) with an Origin header set to a foreign domain, then examine the Access-Control-Allow-Response header
    Affected if The response contains Access-Control-Allow-Origin: * (wildcard) instead of respecting the configured CORS policy
  4. Compare TTS endpoint CORS policy to other endpoints
    Test CORS headers on a different authenticated endpoint (such as /api/v1/chat) and compare the Access-Control-Allow-Origin behavior to that of the TTS endpoint
    Affected if Other endpoints enforce restrictive CORS while the TTS endpoint returns a wildcard origin

You are affected if running Flowise version below 3.1.2 with TTS enabled and the TTS endpoint returns Access-Control-Allow-Origin: * in response headers.

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 version 3.1.2 or later, which corrects the TTS endpoint to respect the server's configured CORS policy via getCorsOptions() instead of using a hardcoded wildcard.

Recommended fix High confidence

3.1.2

  1. Upgrade Flowise to version 3.1.2 or later to resolve the hardcoded CORS wildcard vulnerability in the text-to-speech endpoint

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

Fix this in Flowise Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.

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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-2026-56277 in production — separate from our analysis above.

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