Summary
A serious code injection flaw that affects Langflow versions prior to 1.3.0 is CVE-2025-3248. Through the /api/v1/validate/code endpoint, it enables unauthenticated attackers to run any Python code. The vulnerability has been actively used as the first access vector in the JADEPUFFER ransomware campaign and to spread malware. By requiring authentication for the vulnerable endpoint, Langflow 1.3.0 resolves the problem.
Urgent Actions Required
- Upgrade Langflow to version 1.3.0 or later.
- Restrict or disable external access to the /api/v1/validate/code endpoint if immediate patching is not possible.
- Monitor logs and network activity for suspicious requests targeting the vulnerable endpoint and investigate indicators of compromise.
- Do not expose Langflow to the internet and follow vendor security guidance.
Which Systems Are Vulnerable to CVE-2025-3248?
Technical Overview
- Vulnerability Type: Code Injection Leading to Remote Code Execution (RCE) Due to Missing Authentication
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Affected Software/Versions:
- Langflow versions prior to 1.3.0
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CVSS Vector: v3.1
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Confidentiality Impact: High
- Integrity Impact: High
- Availability Impact: High
- Patch Availability: Yes, available
How Does the CVE-2025-3248 Exploit Work?
The attack typically follows these steps:
What Causes CVE-2025-3248?
Vulnerability Root Cause:
The lack of authentication in Langflow’s /api/v1/validate/code endpoint is the root cause of CVE-2025-3248. Affected versions allow arbitrary Python code to run on the server and cause unauthenticated remote code execution because the endpoint accepts crafted HTTP requests without confirming the identity of the requester.
How Can You Mitigate CVE-2025-3248?
If immediate patching is delayed or not possible:
- Restrict access to the /api/v1/validate/code endpoint using firewall rules or an API gateway.
- Disable or limit public access to vulnerable Langflow instances whenever possible.
- Monitor logs and network traffic for suspicious requests targeting the /api/v1/validate/code endpoint.
- Watch for indicators of compromise and investigate unusual code execution or outbound connections.
- Follow the vendor’s security recommendations until the update to Langflow 1.3.0 can be applied.
Which Assets and Systems Are at Risk?
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Asset Types Affected:
- Langflow Deployments - Running versions prior to 1.3.0
- AI Application Servers - Systems hosting Langflow for AI application and agent workflows
- Internet-Facing Langflow Instances - Especially those exposing the /api/v1/validate/code endpoint
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Business-Critical Systems at Risk:
- AI Infrastructure - Langflow servers that store AI provider API keys and application data
- Cloud-Connected Environments - Deployments where Langflow has access to cloud credentials or secrets
- Deployments with Connected Databases or Configuration Services - If a compromised Langflow instance can access these resources, they may also be exposed
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Exposure Level:
- Internet-Accessible Langflow Instances - Particularly those exposing the vulnerable code validation endpoint
- Unpatched Langflow Servers - Versions earlier than 1.3.0 remain susceptible to unauthenticated remote code execution
Will Patching CVE-2025-3248 Cause Downtime?
Patch application impact: Low. Updating to Langflow 1.3.0 typically involves a standard software upgrade with minimal expected downtime.
How Can You Detect CVE-2025-3248 Exploitation?
Exploitation Signatures:
Monitor for crafted HTTP POST requests targeting the /api/v1/validate/code endpoint, especially those attempting to submit Python code for validation.
MITRE ATT&CK Mapping:
- T1190 - Exploit Public-Facing Application
Indicators of Compromise (IOCs/IOAs):
- Requests targeting the /api/v1/validate/code endpoint
- Unusual processes spawned by the code validation service
- Unexpected outbound network connections
- Suspicious log entries related to the /api/v1/validate/code endpoint
Behavioral Indicators:
- Unauthorized Python code execution through the code validation endpoint
- Unexpected code execution activity on the Langflow server
Alerting Strategy:
- Priority: Critical
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Trigger alerts for:
- Requests to the /api/v1/validate/code endpoint
- Unusual Python code execution on Langflow servers
- Unexpected outbound network connections
Remediation & Response
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Incident Response Considerations:
- Monitor logs for suspicious requests targeting the /api/v1/validate/code endpoint.
- Investigate unusual code execution or outbound network connections from affected Langflow servers.
- Monitor for published indicators of compromise and apply the vendor-recommended update.
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CVSS Breakdown Table
| Metric | Value | Description |
|---|---|---|
| Base Score | 9.8 | Critical severity with a high potential for remote exploitation |
| Attack Vector | Network | Can be exploited remotely over a network |
| Attack Complexity | Low | Does not require special conditions to exploit |
| Privileges Required | None | No authentication or privileges are needed |
| User Interaction | None | No user action is required for exploitation |
| Scope | Unchanged | The impact remains within the vulnerable Langflow component |
| Confidentiality Impact | High | May allow unauthorized access to sensitive information |
| Integrity Impact | High | May enable unauthorized execution or modification of code |
| Availability Impact | High | May disrupt the availability of the affected system through arbitrary code execution |
