CVE-2025-59528

CVE-2025-59528 is a critical-severity vulnerability in Flowiseai Flowise with a CVSS 3.x base score of 10.0. Its EPSS exploit-prediction score of 91% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-94.

Key facts

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.

Frequently asked questions

What is CVE-2025-59528?
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.
How severe is CVE-2025-59528?
CVE-2025-59528 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-59528 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 91% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-59528?
CVE-2025-59528 affects Flowiseai Flowise. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-59528?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-59528 have an EU (EUVD) identifier?
Yes. CVE-2025-59528 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-29246.
When was CVE-2025-59528 published?
CVE-2025-59528 was published on 2025-09-22 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Flowiseai Flowise

All CVEs affecting Flowiseai Flowise →

Other CWE-94 (Code Injection) vulnerabilities

Browse all CWE-94 (Code Injection) vulnerabilities →