Flowise: Unauthenticated Information Disclosure of OAuth Secrets (Cleartext) via GET Request

Exploitation

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

CVSS

5.3 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2026-56270: 2.05% estimated exploitation activity in the next 30 days; percentile 81.24 (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 I have discovered a critical Missing Authentication vulnerability on the /api/v1/loginmethod endpoint. The API allows unauthenticated users (guests) to retrieve the full SSO configuration of any organization by simply providing an organizationId. The response includes sensitive OAuth credentials (Client Secrets) in cleartext. PoC The following request can be sent by anyone on the internet without any cookies or authorization headers. Request Response: The server returns 200 OK with sensitive credentials: Affected Deployments - FlowiseAI Cloud (cloud.flowiseai.com) - Self-hosted FlowiseAI instances where the /api/v1/loginmethod endpoint is exposed Impact An unauthenticated attacker can harvest sensitive API secrets (Google, Microsoft, GitHub Client Secrets) from any organization on the cloud platform. This leads to complete compromise of the organization's third-party integrations and potential data breaches.

Published by the source

16 Apr 2026, 21:20 UTC

Last modified by the source

24 Jun 2026, 13:26 UTC

Source last checked

26 Oct 2026, 12:56 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6pcv-j4jx-m4vx

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-6pcv-j4jx-m4vx

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# Patch Next advisory brief: CVE-2026-56270

Advisory: Flowise: Unauthenticated Information Disclosure of OAuth Secrets (Cleartext) via GET Request
IDs: CVE-2026-56270, GHSA-6pcv-j4jx-m4vx
Record: https://patchnext.com/advisories/cve-2026-56270 (revision 2, source checked 26 Oct 2026, 12:56 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
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-6pcv-j4jx-m4vx (OSV record GHSA-6pcv-j4jx-m4vx lists affected ranges: npm flowise >=0 <3.1.0 (fixed))
- Verified: https://github.com/advisories/GHSA-6pcv-j4jx-m4vx (GitHub-reviewed advisory GHSA-6pcv-j4jx-m4vx lists affected ranges: npm flowise >=0 <=3.0.13)

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