Flowise: Unauthenticated TTS endpoint accepts arbitrary credential IDs — enables API credit abuse via stored credentials

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.2 · 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 · score source

EPSS

• CVE-2026-41279: 0.26% estimated exploitation activity in the next 30 days; percentile 17.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 Docker Validation POST /api/v1/text-to-speech/generate with arbitrary credentialId in body: endpoint processes request, sends SSE ttsstart 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 WHITELISTURLS or validate that the credential belongs to the chatflow being used: --- References -…

Published by the source

17 Apr 2026, 21:35 UTC

Last modified by the source

5 May 2026, 16:11 UTC

Source last checked

26 Oct 2026, 12:50 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-5fw2-mwhh-9947

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-5fw2-mwhh-9947

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# Patch Next advisory brief: CVE-2026-41279

Advisory: Flowise: Unauthenticated TTS endpoint accepts arbitrary credential IDs — enables API credit abuse via stored credentials
IDs: CVE-2026-41279, GHSA-5fw2-mwhh-9947
Record: https://patchnext.com/advisories/cve-2026-41279 (revision 3, source checked 26 Oct 2026, 12:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: flowise 3.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm flowise: affected <= 3.0.13; fixed in 3.1.0

## Suggested inspection (read-only)
- `npm ls flowise --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on flowise.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-5fw2-mwhh-9947 (OSV record GHSA-5fw2-mwhh-9947 lists affected ranges: npm flowise >=0 <3.1.0 (fixed))
- Verified: https://github.com/advisories/GHSA-5fw2-mwhh-9947 (GitHub-reviewed advisory GHSA-5fw2-mwhh-9947 lists affected ranges: npm flowise >=0 <=3.0.13)

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