Summary
A code injection vulnerability in Langflow's code validation API allows submitted Python source to reach a server-side compile and execution path without effective sandboxing. An authenticated attacker who can access the endpoint may execute arbitrary code on the Langflow server.
A code injection vulnerability in Langflow's code validation API allows submitted Python source to reach a server-side compile and execution path without effective sandboxing. An authenticated attacker who can access the endpoint may execute arbitrary code on the Langflow server.
Affected context
The issue occurs in Langflow deployments that expose the /api/v1/validate/code HTTP endpoint and process user-provided Python source through the validation functionality. Risk depends on the endpoint being reachable by an authenticated principal whose permissions are sufficient to submit validation requests, together with the service's ability to execute the supplied code within its server process.
The issue occurs in Langflow deployments that expose the /api/v1/validate/code HTTP endpoint and process user-provided Python source through the validation functionality. Risk depends on the endpoint being reachable by an authenticated principal whose permissions are sufficient to submit validation requests, together with the service's ability to execute the supplied code within its server process.
Exploit preconditions
- Attack surface: HTTP or browser-backed Langflow service
- Required access: Authenticated access capable of submitting requests to the code validation endpoint
- Trigger point: A POST request to
/api/v1/validate/code - Why exploitation is possible: User-controlled Python source is forwarded into a server-side compile/exec path without adequate sandboxing, authorization enforcement, or execution restrictions
- Attack surface: HTTP or browser-backed Langflow service
- Required access: Authenticated access capable of submitting requests to the code validation endpoint
- Trigger point: A POST request to
/api/v1/validate/code - Why exploitation is possible: User-controlled Python source is forwarded into a server-side compile/exec path without adequate sandboxing, authorization enforcement, or execution restrictions
Why this happens
The vulnerability results from treating user-supplied Python source as executable validation input rather than as untrusted data. A validation routine that compiles and executes submitted code without a strong isolation boundary creates a direct code injection condition, mapping to CWE-94: Improper Control of Generation of Code ('Code Injection'). Authentication alone does not provide a safe execution boundary when a user-controlled request can influence server-side interpreter behavior.
The vulnerability results from treating user-supplied Python source as executable validation input rather than as untrusted data. A validation routine that compiles and executes submitted code without a strong isolation boundary creates a direct code injection condition, mapping to CWE-94: Improper Control of Generation of Code ('Code Injection'). Authentication alone does not provide a safe execution boundary when a user-controlled request can influence server-side interpreter behavior.
Potential impact
- An attacker may execute arbitrary Python or operating-system actions in the service process context.
- The attacker could access application secrets, environment variables, or files available to the service account.
- The vulnerability may enable unauthorized modification of workflows, data, or server-side configuration.
- A compromised service could facilitate lateral movement or broader infrastructure compromise, depending on network and runtime privileges.
- An attacker may execute arbitrary Python or operating-system actions in the service process context.
- The attacker could access application secrets, environment variables, or files available to the service account.
- The vulnerability may enable unauthorized modification of workflows, data, or server-side configuration.
- A compromised service could facilitate lateral movement or broader infrastructure compromise, depending on network and runtime privileges.
General mitigation guidance
Mitigation generally focuses on removing server-side execution of untrusted source and reducing the trust placed in validation requests.
Common defensive patterns include:
- Replace compile/exec-based validation with parsing, static inspection, or a narrowly defined declarative representation.
- Enforce explicit authorization and entitlement checks at the endpoint and service layers.
- If dynamic execution is unavoidable, isolate it in a strongly restricted, short-lived sandbox with minimal privileges, limited network access, resource quotas, and no sensitive credentials.
- Apply strict request-size, syntax, and schema controls before processing input.
- Run the application with a least-privilege service identity and segregate secrets from processes handling user-controlled code.
- Treat authenticated users as untrusted for code execution purposes and apply audit logging and rate limits to validation operations.
Mitigation generally focuses on removing server-side execution of untrusted source and reducing the trust placed in validation requests.
Common defensive patterns include:
- Replace compile/exec-based validation with parsing, static inspection, or a narrowly defined declarative representation.
- Enforce explicit authorization and entitlement checks at the endpoint and service layers.
- If dynamic execution is unavoidable, isolate it in a strongly restricted, short-lived sandbox with minimal privileges, limited network access, resource quotas, and no sensitive credentials.
- Apply strict request-size, syntax, and schema controls before processing input.
- Run the application with a least-privilege service identity and segregate secrets from processes handling user-controlled code.
- Treat authenticated users as untrusted for code execution purposes and apply audit logging and rate limits to validation operations.
How teams detect issues like this
Organizations can look for:
- Static analysis findings involving
exec,eval, dynamic compilation, interpreter invocation, or equivalent execution APIs applied to request data. - Code review signals where HTTP request bodies flow into Python compilation or execution without a sandbox boundary.
- Authorization reviews for validation or testing endpoints that accept source code.
- Runtime monitoring for unusual child processes, filesystem access, outbound connections, or secret access originating from the Langflow service.
- Policy enforcement that blocks dynamic code execution in request-handling paths and requires security review for exceptions.
Automated code-scanning and data-flow analysis tools may help identify user-controlled input reaching execution sinks.
Organizations can look for:
- Static analysis findings involving
exec,eval, dynamic compilation, interpreter invocation, or equivalent execution APIs applied to request data. - Code review signals where HTTP request bodies flow into Python compilation or execution without a sandbox boundary.
- Authorization reviews for validation or testing endpoints that accept source code.
- Runtime monitoring for unusual child processes, filesystem access, outbound connections, or secret access originating from the Langflow service.
- Policy enforcement that blocks dynamic code execution in request-handling paths and requires security review for exceptions.
Automated code-scanning and data-flow analysis tools may help identify user-controlled input reaching execution sinks.
Sources
| Source | Link |
|---|---|
| gist. | gist.github.com/ |
| github. | github.com/ |
