Authentication Bypass Vulnerability in Flowise by Caycon
CVE-2026-70636

8.7HIGH

Key Information:

Vendor

Flowiseai

Status
Flowise
Vendor
CVE Published:
6 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-70636?

Flowise versions up to 3.1.4 have a significant security vulnerability that allows unauthenticated attackers to exploit the OAuth2 credential refresh endpoint. This is achieved through a flaw in the prefix-based whitelist matching within the authentication middleware. By sending a specifically crafted POST request to the oauth2-credential refresh route that includes a trailing credential identifier, attackers can bypass all authentication and authorization checks. This breach can lead to unauthorized OAuth token rotations affecting credentials of any workspace, potentially disrupting various OAuth integrations that rely on these tokens. This vulnerability also represents a bypass of a previous issue documented in a related CVE.

Affected Version(s)

Flowise 0 <= 3.1.4

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-70636 - Proof of Concept

References

https://github.com/Caycon/cve-advisories/blob/main/2026/F...
technical-descriptionexploit
https://flowiseai.com/sunset
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

CayCon, piropatriot
.