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CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

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Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

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353,823

Total vulnerabilities in the database

Flowise: Unauthenticated OAuth 2.0 Access Token Disclosure via Public Chatflow in Flowise — flowise

Missing Authentication for Critical Function

Summary

Flowise contains an authentication bypass vulnerability that allows an unauthenticated attacker to obtain OAuth 2.0 access tokens associated with a public chatflow.

By accessing a public chatflow configuration endpoint, an attacker can retrieve internal workflow data, including OAuth credential identifiers, which can then be used to refresh and obtain valid OAuth 2.0 access tokens without authentication.

Details

Flowise is designed to allow public chatflows to be accessed by unauthenticated end users via public URLs or embedded widgets. As a result, chatflowId values are intentionally exposed to unauthenticated clients and must not be treated as secrets.

However, the endpoint GET /api/v1/public-chatbotConfig/<chatflowId> returns internal flowData without authentication. The returned flowData includes workflow node definitions containing OAuth credential identifiers (credential field).

Separately, the endpoint POST /api/v1/oauth2-credential/refresh/<credentialId> allows OAuth. 2.0 tokens to be refreshed without authentication or authorization checks.

Because credential identifiers can be obtained from the unauthenticated public chatflow configuration endpoint, these two behaviors can be combined to allow unauthenticated OAuth 2.0 access token disclosure.

PoC

Prerequisites

Self-hosted Flowise instance
A public chatflow configured with an OAuth 2.0 credential (e.g., Gmail OAuth2)

Step 1: Obtain `chatflowId`

The chatflowId is exposed to unauthenticated users via public chatflow URLs, embedded widgets, or browser network requests when accessing a public chatflow.

Example: d37b9812-72c1-4c64-b152-665f307f755e

Step 2: Retrieve internal `flowData` without authentication

curl -s \
  http://localhost:3000/api/v1/public-chatbotConfig/d37b9812-72c1-4c64-b152-665f307f755e

The response includes flowData containing an OAuth credential identifier, for example:

&quot;credential&quot;: &quot;6efe0e20-ba6f-4fbb-9960-658feffa0542&quot;

Step 3: Refresh OAuth 2.0 token without authentication

curl -X POST \
  http://localhost:3000/api/v1/oauth2-credential/refresh/6efe0e20-ba6f-4fbb-9960-658feffa0542

The response returns valid OAuth 2.0 access token data, including an access_token.

Impact

An unauthenticated attacker can obtain OAuth 2.0 access tokens for third-party services configured in Flowise, potentially leading to unauthorized data access, API abuse, or account compromise.

This vulnerability affects self-hosted deployments because public chatflows are commonly exposed to the internet and require unauthenticated access by design. Treating chatflowId as a secret does not mitigate the issue.

Published: Apr 16, 2026
Updated: Apr 17, 2026
GHSA: GHSA-6f7g-v4pp-r667
Severity: High
Exploit:
CISA KEV:

No technical information available.

CWEs:

CWE-306

Affected Software
References

Software	From	Fixed in
flowise	-	3.1.0

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-6f7g-v4pp-r667

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.