CVE-2025-59528

Published: April 11, 2026

Official Description

Flowise is a drag & drop user interface to build a customized large language model flow. In version 3.0.5, Flowise is vulnerable to remote code execution. The CustomMCP node allows users to input configuration settings for connecting to an external MCP server. This node parses the user-provided mcpServerConfig string to build the MCP server configuration. However, during this process, it executes JavaScript code without any security validation. Specifically, inside the convertToValidJSONString function, user input is directly passed to the Function() constructor, which evaluates and executes the input as JavaScript code. Since this runs with full Node.js runtime privileges, it can access dangerous modules such as child_process and fs. This issue has been patched in version 3.0.6.

NVD Source

Technical Analysis

CVE-2025-59528 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2025-59528 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.

Affected Vendors & Products

Mentioned vendors (from description):

Node.js

CPE data not yet available in NVD for this CVE.

Exploit & PoC Resources

ACTIVE EXPLOITATIONConfirmed exploitation in the wild

Exploit-DB

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

PacketStorm

Security advisories & exploits

External links open in a new tab. Always verify in a controlled environment before use.

News & Research Mentioning CVE-2025-59528

Max severity Flowise RCE vulnerability now exploited in attacks

BleepingComputer· Apr 7, 2026

Hackers are exploiting a maximum-severity vulnerability, tracked as CVE-2025-59528, in the open-source platform Flowise for building custom LLM apps and agentic systems to execute arbitrary code. [...] [xlite_meta score:58 src:BleepingComputer xlite_fp:a8defea151b3abafd6b303664676db033472721617e7ea34f73074ddd8152a68]

Flowise AI Agent Builder Under Active CVSS 10.0 RCE Exploitation; 12,000+ Instances Exposed

The Hacker News· Apr 7, 2026

Threat actors are exploiting a maximum-severity security flaw in Flowise, an open-source artificial intelligence (AI) platform, according to new findings from VulnCheck. The vulnerability in question is CVE-2025-59528 (CVSS score: 10.0), a code injection vulnerability that could result in remote code execution. "The CustomMCP node allows users to input configuration settings for connecting [xlite_meta score:50 src:The Hacker News xlite_fp:2e82bc54078285b34e168c4bc5c6cbcd8f5565693f0ff1832b80341892bb7a55]

Quick Facts

CVE IDCVE-2025-59528

Severity—

CISA KEVYES — Active Exploitation

ExploitIN THE WILD

PublishedApr 11, 2026

Known Threat Actors

financial

core

financial

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2025-59528 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts
!CISA KEV: Federal agencies must patch per BOD 22-01 timeline
!Active exploitation confirmed — treat as P1

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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