CVE-2026-17623: IBM Langflow OSS RCE Vulnerability

CVE-2026-17623 Overview

CVE-2026-17623 is a command injection vulnerability in IBM Langflow OSS versions 1.0.0 through 1.10.3. The flaw resides in the handling of the command field within Model Context Protocol (MCP) server configurations. Improper input validation allows a remote authenticated attacker to execute arbitrary operating system commands on the underlying host. The weakness is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command. Successful exploitation compromises confidentiality, integrity, and availability of the Langflow instance and any data it can reach.

Critical Impact
Authenticated attackers can execute arbitrary OS commands on Langflow hosts, enabling full system compromise, lateral movement, and access to connected AI pipelines and data sources.

Affected Products

IBM Langflow OSS 1.0.0 through 1.10.3
Deployments exposing MCP server configuration endpoints
Downstream integrations relying on vulnerable Langflow instances

Discovery Timeline

2026-08-05 - CVE-2026-17623 published to NVD
2026-08-06 - Last updated in NVD database

Technical Details for CVE-2026-17623

Vulnerability Analysis

Langflow is an open-source framework for building agentic AI workflows. It supports Model Context Protocol (MCP) servers, which are configured through user-supplied fields including a command value that Langflow later executes to launch the MCP process. In versions 1.0.0 through 1.10.3, Langflow does not sufficiently neutralize shell metacharacters or restrict the executable path supplied in that field. An authenticated user with permission to create or edit MCP server configurations can inject arbitrary commands that run in the context of the Langflow service account.

Because Langflow typically runs alongside sensitive assets such as API keys, vector databases, and large language model credentials, code execution on the host exposes the entire AI supply chain. The attack requires network access to the Langflow API and valid credentials, but no user interaction.

Root Cause

The root cause is improper validation and sanitization of the command field before it is passed to a process-execution primitive. The application trusts client-supplied configuration data and forwards it to a subprocess call without allow-listing binaries, quoting arguments, or filtering shell metacharacters. This maps directly to CWE-78.

Attack Vector

An authenticated attacker submits a crafted MCP server configuration through the Langflow web interface or API. The malicious command payload is stored and then invoked by Langflow when the MCP server is started or refreshed. The injected command executes with the privileges of the Langflow process. Because authentication is required but privileges are low, any user with configuration rights, including compromised accounts or over-privileged collaborators, can trigger the flaw.

No verified public exploit code is available. Refer to the IBM Support Page for vendor-provided technical detail.

Detection Methods for CVE-2026-17623

Indicators of Compromise

Unexpected child processes spawned by the Langflow service, particularly shells such as sh, bash, cmd.exe, or powershell.exe.
MCP server configuration entries whose command field contains shell metacharacters (;, |, &&, backticks, $(...)) or references to interpreters not required by legitimate MCP integrations.
Outbound network connections from the Langflow host to unfamiliar IPs following configuration changes.

Detection Strategies

Audit Langflow application logs for MCP configuration create and update events, and correlate them with process-creation telemetry on the host.
Alert on Langflow spawning binaries outside a defined allow-list of MCP runtimes (for example, uvx, npx, or specific Python entry points).
Review authentication logs for accounts creating MCP configurations shortly after login from unusual locations.

Monitoring Recommendations

Forward Langflow, container runtime, and host process telemetry to a centralized analytics platform for cross-source correlation.
Baseline the normal set of processes spawned by Langflow and alert on deviations.
Monitor egress traffic from Langflow workloads for command-and-control patterns following configuration changes.

How to Mitigate CVE-2026-17623

Immediate Actions Required

Upgrade IBM Langflow OSS to a fixed version as published on the IBM Support Page.
Restrict access to Langflow to trusted networks and require multi-factor authentication for all users.
Review existing MCP server configurations and remove any entries with suspicious command values.
Rotate credentials, API tokens, and model provider keys accessible from the Langflow host.

Patch Information

IBM has published remediation guidance and fixed builds through the IBM Support Page. Apply the vendor-recommended version for Langflow OSS deployments and validate the upgrade in a staging environment before production rollout.

Workarounds

Limit MCP configuration permissions to a minimal set of trusted administrators until patches are applied.
Run Langflow inside a hardened container with a read-only filesystem, no shell, and a restricted user, reducing the impact of command execution.
Apply egress network controls so that a compromised Langflow instance cannot reach arbitrary external hosts.
Disable or remove MCP server functionality if it is not required for current workflows.

bash

# Example: run Langflow with a non-root user and restricted capabilities
docker run --rm \
  --user 10001:10001 \
  --read-only \
  --cap-drop=ALL \
  --security-opt no-new-privileges \
  --network langflow-internal \
  -p 7860:7860 \
  langflowai/langflow:<patched-version>