CVE-2026-41273 — flowise
CVE-2026-41273 is a Missing Authentication vulnerability in flowise. A fix is available for flowise — see the affected versions and patch details below.
Flowise: Unauthenticated OAuth 2.0 Access Token Disclosure via Public Chatflow
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-41273.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
flowisenpmDescription
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:
"credential": "6efe0e20-ba6f-4fbb-9960-658feffa0542"
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | all versions | 3.1.0npm install flowise@3.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update flowise to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41273 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-41273 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-41273. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41273 in your dependencies?
O3 Security finds CVE-2026-41273 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.