CVE-2026-0769: 
Homebrew vulnerability analysis and mitigation

CVE-2026-0769 is an eval injection (CWE-95) remote code execution vulnerability in Langflow's eval_custom_component_code function, allowing unauthenticated remote attackers to execute arbitrary Python code on affected installations. The vulnerability was discovered by Peter Girnus (@gothburz) of Trend Micro's Zero Day Initiative (ZDI), reported to the vendor on July 18, 2025, and publicly disclosed as a 0-day advisory on January 9, 2026, after the vendor failed to release a fix. The confirmed affected version is Langflow 1.3.2. It carries a CVSS v3.0 base score of 9.8 (Critical), assigned by ZDI (ZDI Advisory).

The root cause is improper neutralization of directives in dynamically evaluated code (CWE-95), specifically within the eval_custom_component_code function in Langflow. This function accepts user-supplied strings and passes them directly to Python's eval() or equivalent execution mechanism without adequate sanitization or sandboxing, enabling arbitrary Python code execution. No authentication is required, and exploitation requires no user interaction — an attacker need only send a crafted HTTP request to the vulnerable endpoint. The vulnerability was tracked internally as ZDI-CAN-26972 (ZDI Advisory).

Successful exploitation grants an unauthenticated remote attacker arbitrary code execution in the context of the Langflow process, resulting in full compromise of confidentiality, integrity, and availability of the affected system. Attackers can exfiltrate sensitive data, install malware or backdoors, modify or destroy data, and use the compromised host as a pivot point for lateral movement within the network. Given that Langflow is an AI/LLM workflow platform, sensitive API keys, model configurations, and connected data sources may also be at risk (ZDI Advisory).

The vulnerability was published as a 0-day advisory by ZDI on January 9, 2026, after the vendor did not respond adequately to repeated follow-ups over nearly six months. A proof-of-concept exploit reference is available via the ZDI advisory; no evidence of active in-the-wild exploitation has been confirmed at the time of disclosure. The EPSS score is approximately 0.0124 (1.24%), and the vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. No specific threat actor attribution has been reported (ZDI Advisory).

1. Reconnaissance: Identify internet-facing Langflow instances (version 1.3.2) using tools like Shodan or Censys, searching for Langflow's default web interface or API endpoints.
2. Locate the vulnerable endpoint: Identify the API endpoint that invokes the eval_custom_component_code function, typically accessible via Langflow's REST API for custom component code evaluation.
3. Craft malicious payload: Prepare a Python code payload (e.g., a reverse shell or command execution snippet) to be injected as the user-supplied string parameter.
4. Send unauthenticated request: Submit an HTTP POST request to the vulnerable endpoint with the malicious Python code as the payload — no authentication headers or tokens are required.
5. Achieve code execution: The server evaluates the injected Python code in the context of the Langflow process, granting the attacker arbitrary command execution, enabling reverse shell establishment, data exfiltration, or further lateral movement (ZDI Advisory).

• Network: Unexpected outbound connections from the Langflow server to external IPs or domains; unusual HTTP POST requests to Langflow API endpoints related to custom component code evaluation with large or encoded payloads.
• Process: Unusual child processes spawned by the Langflow Python process (e.g., bash, sh, curl, wget, python3 executing unexpected commands); new network listeners or reverse shell connections initiated by the Langflow process.
• File System: Unexpected scripts, web shells, or binaries written to the Langflow installation directory or temp directories; new cron jobs or scheduled tasks created under the Langflow service account.
• Logs: Langflow application logs showing unexpected or malformed code strings submitted to the eval_custom_component_code function; Python tracebacks or errors related to eval execution of unusual code patterns.

As of the disclosure date, no vendor patch is available for CVE-2026-0769 — the vendor did not release a fix despite being notified in July 2025. The primary recommended mitigation is to restrict network access to Langflow installations, allowing only authorized users and trusted networks to reach the service (e.g., via firewall rules, VPN, or network segmentation). Organizations should consider isolating Langflow instances from critical systems and sensitive data, and monitor for anomalous activity until a patch is released. Users should follow the Langflow GitHub repository for any forthcoming security updates (ZDI Advisory).

The ZDI published the advisory as a 0-day on January 9, 2026, explicitly noting the vendor's lack of response over nearly six months, which drew attention to Langflow's vulnerability disclosure practices. The advisory was picked up by security aggregators including VulDB, Vulners, and The Hacker Wire, and discussed on social platforms including Mastodon and Bluesky. Check Point also referenced the vulnerability in a defense advisory (CPAI-2026-4008). Community sentiment reflects concern over the unpatched critical severity and the vendor's unresponsiveness to coordinated disclosure (ZDI Advisory).