Flowise: Unauthenticated OAuth2 Refresh Enables Non-Blind SSRF and Secret Exfiltration

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the OAuth2 token refresh endpoint POST /api/v1/oauth2-credential/refresh/:credentialId is unauthenticated by design and performs a server-side HTTP request to the credential-controlled accessTokenUrl without SSRF protections. Runtime validation confirmed that the endpoint was reachable without authentication, triggered outbound POST requests to an attacker-controlled server, reflected the full remote response body to the caller through tokenInfo, and sent client_id, client_secret, grant_type=refresh_token, and refresh_token in the request body. This issue is fixed in version 3.1.3.

Source published

4 Aug 2026 14:20:35 UTC

Source modified

4 Aug 2026 19:52:53 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N