How severe is CVE-2025-59528?

CVE-2025-59528 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-59528?

CVE-2025-59528 affects the following packages: flowise (npm). Ecosystems affected: npm.

How do I fix CVE-2025-59528?

Update flowise to version 3.0.6 or later. Run your dependency manager's update command and verify no transitive dependencies pin the vulnerable version. Use O3 Security's SCA scanner to confirm the fix is applied across your entire dependency tree.

Is CVE-2025-59528 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2025-59528, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2025-59528?

CVE-2025-59528 has an EPSS (Exploit Prediction Scoring System) score of 90.4%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2025-59528?

CVE-2025-59528 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2025-59528?

A Nuclei detection template exists for CVE-2025-59528, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2025-59528 published, and has it been updated?

CVE-2025-59528 was published on September 22, 2025 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-59528: Flowise has Remote Code Execution vulnerability…

EPSS Exploitation Probability

via FIRST.org ↗

90.4%probability of exploitation in next 30 days

Very High Risk100th percentile+3.59%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦flowise

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`flowise`	≥ 3.0.5&&< 3.0.6	3.0.6

Frequently Asked Questions

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 t

O3 Security · Impact-Aware SCA

Is CVE-2025-59528 in your stack?

O3 detects CVE-2025-59528 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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