A critical remote code execution vulnerability, CVE-2026-0769, has been identified in multiple Langflow products. This flaw allows an unauthenticated remote attacker to execute arbitrary code on a vulnerable server by sending a specially crafted request, potentially leading to a complete system compromise. Due to its high severity and lack of a required authentication, immediate remediation is strongly advised.

This is a critical eval injection vulnerability that exists within the eval_custom_component_code function. The function fails to properly sanitize or validate a user-supplied string before passing it to a Python evaluation mechanism. A remote, unauthenticated attacker can submit a request containing malicious Python code, which the application will then execute with the privileges of the Langflow process, resulting in remote code execution (RCE).

This vulnerability is rated as critical severity with a CVSS score of 9.8. Successful exploitation could lead to a complete compromise of the affected server, granting an attacker full control. Potential consequences include theft of sensitive data processed by the application, deployment of ransomware, lateral movement into the broader corporate network, and service disruption. The lack of an authentication requirement significantly increases the risk, as any attacker with network access to the application can attempt exploitation, posing a severe threat to data confidentiality, integrity, and availability.

Immediate Action:

• Patch: Immediately apply the security updates provided by the vendor. Update all affected Langflow installations to the latest version that addresses this vulnerability.
• Review Logs: After patching, review application and server access logs for any indicators of compromise or exploitation attempts targeting the vulnerable function.

Proactive Monitoring:

• Log Analysis: Monitor application logs for requests to the endpoint associated with the eval_custom_component_code function. Scrutinize requests for suspicious payloads containing Python keywords like import, os, subprocess, eval, or exec.
• Network Traffic Analysis: Monitor for anomalous outbound network connections from Langflow servers, which could indicate a reverse shell or data exfiltration.
• Endpoint Detection: Look for unexpected child processes spawned by the Langflow application process (e.g., sh, bash, powershell.exe, curl, wget).

Compensating Controls: If patching cannot be performed immediately, implement the following controls:

• Web Application Firewall (WAF): Deploy a WAF with rules designed to block requests containing common code injection patterns and Python execution syntax.
• Network Segmentation: Restrict network access to the Langflow application, allowing connections only from trusted IP addresses. Limit the server's outbound network connectivity to prevent attackers from establishing reverse shells.
• Principle of Least Privilege: Ensure the Langflow application is running with the minimum privileges necessary for its operation to limit the impact of a potential compromise.

Public Exploit Available: false

Given the critical CVSS score of 9.8 and the fact that no authentication is required for exploitation, CVE-2026-0769 represents a significant and immediate threat to affected organizations. We strongly recommend that all vulnerable Langflow instances be patched immediately. While this vulnerability is not currently listed on the CISA KEV (Known Exploited Vulnerabilities) catalog, its characteristics make it a prime candidate for future inclusion and widespread exploitation. Organizations should prioritize this remediation effort and treat any suspected exploitation attempts as a full-scale compromise requiring an incident response investigation.