Vulnerability · Published Aug 6, 2026 · Assigned by VulnCheck

CVE-2026-70636Flowise 3.1.4 Authentication Bypass via OAuth2 Credential Refresh Endpoint

High 7.5

In plain English

A high-severity missing authorization in Flowise from FlowiseAI. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.7%top 48.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Flowise through 3.1.4 contains an authentication bypass vulnerability that allows unauthenticated attackers to access the OAuth2 credential refresh endpoint by exploiting prefix-based whitelist matching in the authentication middleware defined in packages/server/src/utils/constants.ts. Attackers can send a POST request to the oauth2-credential refresh route with a trailing credential identifier to bypass all authentication and authorization checks, triggering unauthorized OAuth token rotation against credentials belonging to any workspace and potentially disrupting dependent OAuth integrations. This is a bypass of CVE-2026-41273.

Affected products (as reported)

Vendor	Product	Versions
FlowiseAI	Flowise	0 – through 3.1.4

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

Researcher Disclosure technical-description, exploit
Sunset Announcement vendor-advisory
https://www.vulncheck.com/advisories/flowise-authentication-bypass-via-oauth2-credential-refresh-endpoint third-party-advisory