Code Injection in Flowise - CVE-2025-59528
Published: April 9, 2026 / Updated: April 23, 2026
Vulnerability identifier: #VU125540
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-59528
CWE-ID: CWE-94
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to improper control of code generation in the CustomMCP node when processing a user-supplied mcpServerConfig value through the /api/v1/node-load-method/customMCP endpoint. A remote attacker can send a specially crafted request to execute arbitrary code.
The input is evaluated through the Function() constructor in the Node.js runtime context, which can expose modules such as child_process and fs.
Affected software
Flowise
How to mitigate CVE-2025-59528
Install security update from vendor's website.
Flowise - update to 3.0.6
Links to Public Exploits and PoC-codes
- Exploit #12621 - CVE-2025-58434-59528 (April 23, 2026)
- Exploit #12604 - -CVE-2025-59528-PoC (A simple python script to exploit CVE-2025-59528, this an Authenticated RCE vulnerability in Flowise application, a popular AI tool. That is also used in HTB seasonal challenge. The issue is present in version <= 3.0.5, for more detai (April 17, 2026)
- Exploit #12601 - CVE-2025-58434-AND-59528-POC (April 17, 2026)
- Exploit #12562 - Flowise JS Injection RCE (April 9, 2026)