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

Severity: critical (CVSS 10.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-04 · updated 2026-10-24
Weakness: CWE-200

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.

Affected products

FlowiseAI Flowise: before 3.1.3 — fixed in 3.1.3

How to fix

Upgrade to a fixed version: FlowiseAI Flowise 3.1.3. Check the vendor advisory for mitigations.

References

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