Critical CVE-2025-59528 Vulnerability Discovered in Flowise Platform
Security researchers discovered CVE-2025-59528 on April 7, 2026, a maximum-severity vulnerability in Flowise, the popular open-source platform used for building custom large language model applications and agentic AI systems. The flaw enables remote attackers to execute arbitrary code on vulnerable Flowise installations without authentication, making it an immediate threat to organizations deploying AI workflows.
Flowise serves as a low-code platform that allows developers and data scientists to create sophisticated LLM-powered applications through a visual interface. The platform integrates with major AI models including OpenAI's GPT series, Anthropic's Claude, and various open-source alternatives. Organizations use Flowise to build chatbots, document analysis systems, and automated reasoning applications across enterprise environments.
The vulnerability stems from improper input validation in Flowise's API endpoints that handle user-submitted workflow configurations. Attackers can craft malicious payloads within workflow definitions that bypass security controls and execute system commands on the underlying server. SecurityWeek reports that the exploitation method involves manipulating JSON parameters in workflow creation requests to inject shell commands.
Security researchers at multiple firms independently identified active exploitation attempts targeting internet-facing Flowise instances. The attacks typically begin with reconnaissance scans to identify vulnerable installations, followed by payload delivery through crafted HTTP requests to the platform's REST API. Successful exploitation grants attackers complete control over the host system, including access to AI model configurations, training data, and connected databases.
The timing of this vulnerability is particularly concerning given the rapid adoption of AI development platforms across enterprise environments. Many organizations have deployed Flowise instances to experiment with LLM integration without implementing proper security hardening measures. The platform's ease of deployment has led to numerous exposed installations accessible from the public internet.
Flowise Installations Across All Versions Face Immediate Risk
All versions of Flowise prior to the emergency patch released on April 7, 2026, contain the CVE-2025-59528 vulnerability. This includes both self-hosted installations and cloud-deployed instances across major platforms including AWS, Azure, Google Cloud, and DigitalOcean. Organizations running Flowise in Docker containers, Kubernetes clusters, or traditional virtual machines are equally vulnerable to exploitation.
The vulnerability particularly impacts enterprises that have deployed Flowise for production AI workflows, including financial services firms using the platform for document processing, healthcare organizations implementing clinical decision support systems, and technology companies building customer service automation. Educational institutions running Flowise for AI research and development also face significant exposure.
Internet scanning data reveals approximately 15,000 publicly accessible Flowise instances worldwide, with the highest concentrations in North America, Europe, and Asia-Pacific regions. Many of these installations lack proper network segmentation or access controls, making them prime targets for automated exploitation campaigns. Organizations using default configurations are at highest risk, as the vulnerability can be triggered through standard API endpoints without special privileges.
Cloud service providers hosting Flowise instances have begun issuing security advisories to customers, recommending immediate patching and network isolation measures. The vulnerability affects both single-tenant and multi-tenant deployments, though proper container isolation can limit the blast radius of successful attacks.
Immediate Patching and Mitigation Steps for CVE-2025-59528
Organizations must immediately update Flowise to version 1.6.5 or later, which contains the security fix for CVE-2025-59528. The patch addresses the input validation flaw by implementing strict sanitization of workflow configuration parameters and adding authentication requirements for sensitive API endpoints. Administrators can download the updated version from the official Flowise GitHub repository or update existing installations using npm package manager commands.
For Docker deployments, pull the latest flowise:latest image and restart containers with the updated version. Kubernetes users should update their deployment manifests to reference the patched image tag and perform rolling updates to minimize service disruption. Cloud marketplace installations require updating through the respective platform's update mechanisms, with AWS, Azure, and Google Cloud providing automated update options for managed Flowise services.
As an immediate workaround for systems that cannot be patched immediately, administrators should implement network-level access controls to restrict Flowise API access to trusted IP ranges only. Configure web application firewalls to block requests containing suspicious payloads targeting workflow creation endpoints. Additionally, run Flowise instances behind reverse proxies with strict request validation and rate limiting to reduce attack surface exposure.
Security teams should audit existing Flowise logs for indicators of compromise, including unusual API requests to workflow endpoints, unexpected system process creation, and unauthorized file modifications. Monitor for HTTP POST requests to /api/v1/chatflows endpoints containing encoded or obfuscated content that could indicate exploitation attempts. The Hacker News provides additional technical details on detection signatures for this vulnerability class.
