CVE-2026-70478 Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service

Critical 9.2 Published 4 Aug 2026 Updated 5 Aug 2026

Unauthenticated access to an OAuth2 refresh endpoint allows attackers to steal access tokens for connected services, leading to unauthorized data access and account takeover.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-70478?

CVE-2026-70478 is a critical vulnerability in Flowiseai Flowise, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.

Weakness: CWE-200

Which versions are affected by CVE-2026-70478?

2 open source packages ship an affected version, including flowise. It affects 1 product.

Package	Affected	Fixed in
`flowise` npm	All versions	`3.1.3`
`flowise` npm	All versions	`3.1.3`

Products include Flowiseai Flowise.

How do I fix CVE-2026-70478?

Upgrade flowise to 3.1.3 or later.

Is CVE-2026-70478 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-70478 exists.

All Flowiseai Flowise vulnerabilities

Sources

Also known as GHSA-qgvm-j2hm-6m38.