CVE-2026-41268: Flowise RCE Vulnerability

CVE-2026-41268 Overview

CVE-2026-41268 is a critical unauthenticated remote command execution (RCE) vulnerability affecting Flowise, a popular drag & drop user interface for building customized large language model (LLM) flows. Prior to version 3.1.0, attackers can exploit this vulnerability to execute arbitrary system commands with root privileges within containerized Flowise instances without any authentication or prior knowledge of the target system.

The vulnerability is exploited via a parameter override bypass using the FILE-STORAGE:: keyword combined with a NODE_OPTIONS environment variable injection. This attack requires only a single HTTP request, making it trivial to exploit at scale against exposed Flowise deployments.

Critical Impact
Unauthenticated attackers can achieve full system compromise of Flowise instances with root-level command execution, potentially leading to data exfiltration, lateral movement, and complete infrastructure takeover.

Affected Products

Flowise versions prior to 3.1.0
Containerized Flowise deployments
Self-hosted Flowise instances exposed to the network

Discovery Timeline

2026-04-23 - CVE-2026-41268 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2026-41268

Vulnerability Analysis

This vulnerability is classified under CWE-20 (Improper Input Validation), stemming from insufficient validation of user-controlled parameters within Flowise's request handling mechanism. The flaw allows attackers to bypass security controls by leveraging the FILE-STORAGE:: keyword prefix in parameter values, which triggers a different code path that fails to properly sanitize input.

The attack chain involves injecting malicious values into the NODE_OPTIONS environment variable through the parameter override mechanism. Node.js applications are particularly susceptible to NODE_OPTIONS injection because this environment variable can modify the runtime behavior of the Node.js process, including loading arbitrary modules or executing code at startup.

Within containerized deployments running as root (a common misconfiguration), successful exploitation grants the attacker complete control over the container with elevated privileges, enabling them to access sensitive data, modify application logic, or pivot to other systems.

Root Cause

The root cause is improper input validation in the parameter handling logic. When parameters contain the FILE-STORAGE:: prefix, the application processes them through a separate code path that does not adequately sanitize or validate the input before using it in security-sensitive operations. This oversight allows environment variable injection, specifically targeting NODE_OPTIONS, which Node.js uses to configure runtime options for the JavaScript engine.

Attack Vector

The attack is network-based and requires no authentication. An attacker sends a specially crafted HTTP request to a vulnerable Flowise instance, using the FILE-STORAGE:: keyword to bypass parameter validation. The payload injects malicious values into NODE_OPTIONS, which are then interpreted by the Node.js runtime. When triggered, this allows execution of arbitrary system commands with the privileges of the Flowise process—typically root in containerized environments.

The attack complexity is considered high due to the specific conditions required for exploitation, but the impact is severe given that no authentication or user interaction is necessary.

Detection Methods for CVE-2026-41268

Indicators of Compromise

Unusual HTTP requests containing FILE-STORAGE:: patterns in request parameters or body content
Evidence of NODE_OPTIONS environment variable manipulation in application logs
Unexpected child processes spawned by the Flowise Node.js process
Anomalous outbound network connections from Flowise containers

Detection Strategies

Monitor HTTP request logs for requests containing FILE-STORAGE:: strings combined with environment variable names like NODE_OPTIONS
Implement Web Application Firewall (WAF) rules to detect and block requests with suspicious parameter patterns
Deploy runtime application self-protection (RASP) solutions to detect command injection attempts
Review container logs for unexpected process execution or privilege escalation events

Monitoring Recommendations

Enable detailed logging for all Flowise API endpoints and review for anomalous parameter values
Configure alerting on process creation events within Flowise containers, particularly for shell commands
Monitor network traffic for unusual egress patterns from Flowise instances that may indicate post-exploitation activity
Implement integrity monitoring on critical Flowise application files to detect tampering

How to Mitigate CVE-2026-41268

Immediate Actions Required

Upgrade Flowise to version 3.1.0 or later immediately to address this vulnerability
If immediate patching is not possible, restrict network access to Flowise instances to trusted IP ranges only
Review and audit all Flowise deployments for signs of prior compromise
Ensure Flowise containers are not running as root to limit the impact of potential exploitation

Patch Information

This vulnerability is fixed in Flowise version 3.1.0. Organizations should upgrade to this version or later to fully remediate the issue. For detailed information about the fix, refer to the GitHub Security Advisory.

Workarounds

Place Flowise behind an authenticated reverse proxy to prevent unauthenticated access
Implement network segmentation to isolate Flowise instances from critical infrastructure
Use Web Application Firewall rules to block requests containing FILE-STORAGE:: patterns
Run Flowise containers with non-root users and minimal capabilities to reduce exploitation impact

bash

# Run Flowise container with non-root user and restricted capabilities
docker run -d \
  --user 1000:1000 \
  --cap-drop=ALL \
  --read-only \
  --network=internal \
  flowiseai/flowise:3.1.0