CVE-2026-41279: Flowise Unauthenticated TTS Endpoint Accepts Arbitrary Vulnerability

HIGH
Advisory Identifier: GHSA-5fw2-mwhh-9947
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CVSS 7.5
CWE-639
Published
Advisory Summary

CVE-2026-41279 is a HIGH (CVSS 7.5) unauthenticated tts endpoint accepts arbitrary vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Flowise libraries in the npm ecosystem. The issue involves unauthenticated tts endpoint accepts arbitrary credential ids — enables api credit abuse via stored credentials. Remediation is available by upgrading affected packages to version 3.1.0.

CVE-2026-41279 at a Glance

CVE Identifier CVE-2026-41279
GHSA Identifier GHSA-5fw2-mwhh-9947
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Flowise
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-41279

To remediate this vulnerability, upgrade all affected Flowise dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

flowise fixed: 3.1.0 
npm install flowise@3.1.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls flowise

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-41279, inspect your project dependencies using npm:

npm ls flowise

Analyze the terminal output to locate any version of Flowise in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.1.0), your application is affected.

Note: The npm ls flowise command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In Flowise, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The text-to-speech generation endpoint (`POST /api/v1/text-to-speech/generate`) is whitelisted (no auth) and accepts a `credentialId` directly in the request body. When called without a `chatflowId`, the endpoint uses the provided `credentialId` to decrypt the stored credential (e.g., OpenAI or ElevenLabs API key) and generate speech. ### Root Cause ```typescript // packages/server/src/controllers/text-to-speech/index.ts:58-64 } else { // Use TTS config from request body provider = bodyProvider credentialId = bodyCredentialId // ← attacker-controlled credential ID voice = bodyVoice model = bodyModel } ``` ### Docker Validation `POST /api/v1/text-to-speech/generate` with arbitrary `credentialId` in body: endpoint processes request, sends SSE `tts_start` event, only fails when credential doesn't exist — proves code path runs without authentication. ### Impact - Use victim's API keys (OpenAI, ElevenLabs, Azure, Google) without authorization - Burn API credits on the victim's account - Generate unlimited speech content at victim's expense - Combined with credential ID leak from Finding 2, this is trivially exploitable ### Suggested Fix Remove the TTS endpoint from `WHITELIST_URLS` or validate that the credential belongs to the chatflow being used: ```typescript // Only allow credentialId when it matches the chatflow's TTS configuration if (!chatflowId) { return res.status(401).json({ message: 'Authentication required' }) } ``` --- ## References - `packages/server/src/controllers/text-to-speech/index.ts` lines 10-162 - `packages/server/src/utils/constants.ts` line 41 (whitelist entry) ## Credits - Shinobi Security - https://github.com/shinobisecurity

CVE-2026-41279 Affected Flowise Versions

1 component(s)
Fixed Versions:
3.1.0
Product / Package Ecosystem Affected Versions Fixed Version
flowise
npm/flowise
npm
< 3.1.0
3.1.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-5fw2-mwhh-9947
NVD — CVE-2026-41279 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-41279
Flowise Source Repository REPOSITORY
https://github.com/FlowiseAI/Flowise

Frequently Asked Questions

What is CVE-2026-41279?
CVE-2026-41279 is a security vulnerability in Flowise involving Unauthenticated TTS endpoint accepts arbitrary credential IDs — enables API credit abuse via stored credentials under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Flowise versions are affected?
Affected versions include releases prior to 3.1.0 across affected packages: flowise.
What version fixes CVE-2026-41279?
Upgrading to 3.1.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is flowise affected?
Yes, flowise is affected in releases prior to 3.1.0. Upgrade your dependency to 3.1.0 or later.
What is the CVSS score of CVE-2026-41279?
CVE-2026-41279 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-41279?
CVE-2026-41279 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check npm dependencies for CVE-2026-41279?
Run the dependency tree command: 'npm ls flowise'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5fw2-mwhh-9947",
  "modified" : "2026-04-24T21:00:53Z",
  "published" : "2026-04-17T21:35:14Z",
  "aliases" : [ "CVE-2026-41279" ],
  "summary" : "Flowise: Unauthenticated TTS endpoint accepts arbitrary credential IDs — enables API credit abuse via stored credentials",
  "details" : "### Summary\n\nThe text-to-speech generation endpoint (`POST /api/v1/text-to-speech/generate`) is whitelisted (no auth) and accepts a `credentialId` directly in the request body. When called without a `chatflowId`, the endpoint uses the provided `credentialId` to decrypt the stored credential (e.g., OpenAI or ElevenLabs API key) and generate speech.\n\n### Root Cause\n\n```typescript\n// packages/server/src/controllers/text-to-speech/index.ts:58-64\n} else {\n    // Use TTS config from request body\n    provider = bodyProvider\n    credentialId = bodyCredentialId  // ← attacker-controlled credential ID\n    voice = bodyVoice\n    model = bodyModel\n}\n```\n\n### Docker Validation\n\n`POST /api/v1/text-to-speech/generate` with arbitrary `credentialId` in body: endpoint processes request, sends SSE `tts_start` event, only fails when credential doesn't exist — proves code path runs without authentication.\n\n### Impact\n\n- Use victim's API keys (OpenAI, ElevenLabs, Azure, Google) without authorization\n- Burn API credits on the victim's account\n- Generate unlimited speech content at victim's expense\n- Combined with credential ID leak from Finding 2, this is trivially exploitable\n\n### Suggested Fix\n\nRemove the TTS endpoint from `WHITELIST_URLS` or validate that the credential belongs to the chatflow being used:\n\n```typescript\n// Only allow credentialId when it matches the chatflow's TTS configuration\nif (!chatflowId) {\n    return res.status(401).json({ message: 'Authentication required' })\n}\n```\n\n---\n\n## References\n\n- `packages/server/src/controllers/text-to-speech/index.ts` lines 10-162\n- `packages/server/src/utils/constants.ts` line 41 (whitelist entry)\n\n## Credits\n- Shinobi Security - https://github.com/shinobisecurity",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "flowise"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.0.13"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-5fw2-mwhh-9947"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41279"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/FlowiseAI/Flowise"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-17T21:35:14Z",
    "nvd_published_at" : "2026-04-23T20:16:16Z"
  }
}