A flaw in Flowise’s SSO login path allows an authentication bypass, which is a classic instance of CWE‑287: Improper Authentication. The bypass occurs when the callback from an SSO provider contains an email that matches a pending invitee; the system mistakenly copies the invitation‑token from the server’s database into the registration flow and validates it as if it were supplied by the attacker. As a result, the attacker can activate the invite and become an active member of the organization without knowing the original invitation code or privileged credentials. The impact is the ability to assume the role and permissions of the invited user, potentially exposing sensitive data or allowing further lateral movement.

Flowise AI’s Flowise product, version 3.1.4, is affected when the application runs in enterprise or platform mode with SSO authentication enabled. Any tenant using this configuration and issuing new invitations is susceptible until a patch is applied.

The vulnerability has a CVSS v3.1 score of 9.2, indicating very high severity. No EPSS score is available and the flaw is not listed in the CISA Known Exploit Vulnerabilities catalog. The likely attack vector is remote via an SSO provider: an attacker needs only the ability to trigger an SSO callback with the target’s pending invitee email and the invitation must still be within the default 24‑hour validity window. Once triggered, the attacker can take over the invitation and gain active organization membership with no additional credentials.