CVE-2026-30823: 
Flowise vulnerability analysis and mitigation

CVE-2026-30823 is a critical Insecure Direct Object Reference (IDOR) vulnerability combined with a Business Logic Flaw in FlowiseAI's Flowise platform, affecting all versions up to and including 3.0.12. The vulnerability exists in the PUT /api/v1/loginmethod endpoint, which fails to validate whether an authenticated user has ownership or administrative rights over a target organizationId, enabling account takeover and enterprise feature bypass. It was discovered and published on March 5, 2026, with the patch released in version 3.0.13. The CVSS v3 base score is 8.8 (High) (GitHub Advisory, Flowise Advisory).

The root cause is a missing server-side authorization check (CWE-639: Authorization Bypass Through User-Controlled Key; CWE-862: Missing Authorization) in the PUT /api/v1/loginmethod endpoint. The backend accepts the organizationId parameter directly from the JSON request body and updates the corresponding database record without verifying that request.user.organizationId === body.organizationId. Any authenticated user — including those on the free tier — can supply an arbitrary organizationId belonging to another organization and overwrite its SSO/OAuth configuration. The full proof-of-concept HTTP request, including the malicious clientID and clientSecret payload, is publicly documented in the GitHub security advisory (GitHub Advisory, Flowise Advisory).

Successful exploitation enables two distinct attack scenarios: account takeover and license control bypass. In the account takeover scenario, an attacker replaces a victim organization's legitimate OAuth credentials (e.g., Google Client ID/Secret) with their own malicious application credentials, causing victim employees who attempt SSO login to authenticate against the attacker's application — enabling session hijacking and credential theft. In the license bypass scenario, free-tier users can illicitly enable and configure Enterprise-only SSO providers (Google, Azure, Okta, etc.) without a valid license, undermining the platform's access control model. The confidentiality, integrity, and availability impacts are all rated High (GitHub Advisory).

A detailed proof-of-concept exploit — including a complete HTTP request with specific payload structure — is publicly available in the GitHub security advisory, and Feedly classifies it as a real exploit with high confidence (Flowise Advisory). Exploitation requires only a low-privileged authenticated account (e.g., a free-tier registration), making the barrier to exploitation very low. The EPSS score is approximately 0.033% (0.000160 raw), indicating a currently low probability of active exploitation within 30 days. There is no evidence of in-the-wild exploitation at this time, and the vulnerability is not listed in the CISA KEV catalog (GitHub Advisory).

1. Create a free account: Register a standard "Free" tier account on the target Flowise instance (e.g., cloud.flowiseai.com) and obtain a valid JWT authentication token from the login response cookie or header.
2. Identify the target organizationId: Enumerate or discover the victim organization's organizationId UUID (e.g., bd2b74e0-e0cd-4bb5-ba98-3cc2ae683d5d) through API responses, shared links, or other information disclosure vectors.
3. Register a malicious OAuth application: Create a Google (or Azure/Okta) OAuth application under the attacker's control and obtain a clientID and clientSecret for that application.
4. Send the malicious PUT request: Issue the following authenticated request to overwrite the victim organization's SSO configuration:

PUT /api/v1/loginmethod HTTP/2
Host: cloud.flowiseai.com
Cookie: token=<ATTACKER_JWT>
Content-Type: application/json

{
  "organizationId": "bd2b74e0-e0cd-4bb5-ba98-3cc2ae683d5d",
  "userId": "<any_user_id>",
  "providers": [{
    "providerLabel": "Google",
    "providerName": "google",
    "config": {
      "clientID": "ATTACKER_MALICIOUS_CLIENT_ID",
      "clientSecret": "ATTACKER_MALICIOUS_SECRET"
    },
    "status": "enable"
  }]
}

5. Confirm success: The server responds with 200 OK and the victim's organizationId, confirming the SSO configuration has been overwritten.
6. Harvest credentials: When victim employees attempt to log in via Google SSO, they are redirected through the attacker's OAuth application, allowing the attacker to capture authorization codes, access tokens, or session credentials (Flowise Advisory).

• Network: Unexpected PUT requests to /api/v1/loginmethod originating from IP addresses or user accounts not associated with the target organization's administrators; requests where the organizationId in the JSON body does not match the authenticated user's organization.
• Logs: API access logs showing PUT /api/v1/loginmethod returning 200 OK for a user whose account belongs to a different organization than the organizationId in the request body; repeated SSO configuration changes in a short time window.
• Application/Database: Unexpected changes to OAuth clientID or clientSecret values in the SSO configuration for an organization; SSO providers (Google, Azure, Okta) enabled for organizations on the Free tier that should not have Enterprise features.
• Authentication Events: Victim employees experiencing SSO login failures or being redirected to unfamiliar OAuth consent screens; authentication events logged against an unrecognized OAuth application ID (Flowise Advisory).

Upgrade Flowise to version 3.0.13 or later, which includes the fix fix: update loginmethod endpoints (PR #5681) that enforces proper authorization checks on the PUT /api/v1/loginmethod endpoint (Flowise Release). As an interim workaround where immediate upgrade is not possible, restrict network access to the /api/v1/loginmethod endpoint to trusted administrative IP ranges only. Additionally, audit existing SSO configurations for all organizations to detect any unauthorized modifications to OAuth credentials, and implement monitoring/alerting for unexpected changes to SSO provider settings (GitHub Advisory).

The vulnerability was reported by security researcher berkdedekarginoglu and published by igor-magun-wd to the FlowiseAI repository on March 5, 2026 (Flowise Advisory). The Hacker Wire covered the disclosure with an article titled "Flowise IDOR Leads to Account Takeover & SSO Bypass," highlighting the severity of the authentication flow hijacking scenario (The Hacker Wire). Additional coverage appeared on InfinitSec, which published a technical breakdown of the IDOR chain leading to account takeover and enterprise feature bypass.