langflow-ai Langflow up to 1.9.3 Code Validation Endpoint validate.py post_validate_code code injection

Summaryinfo

A vulnerability, which was classified as critical, was found in langflow-ai Langflow up to 1.9.3. This issue affects the function post_validate_code of the file src/backend/base/langflow/api/v1/validate.py of the component Code Validation Endpoint. Executing a manipulation can lead to code injection. The identification of this vulnerability is CVE-2026-51886. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in langflow-ai Langflow up to 1.9.3 and classified as critical. This vulnerability affects the function post_validate_code of the file src/backend/base/langflow/api/v1/validate.py of the component Code Validation Endpoint. The manipulation with an unknown input leads to a code injection vulnerability. The CWE definition for the vulnerability is CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

langflow-ai langflow v1.9.3 is affected by: Code Injection. The impact is: execute arbitrary code (remote). The component is: src/backend/base/langflow/api/v1/validate.py:validate-post_validate_code-a-real-authenticated-http-post-to-api-v1. The attack vector is: Attack surface: HTTP or browser-backed service path. A public-facing route accepts raw Python source and forwards it into a server-side compile/exec validation path without any visible entitlement guard. ¶¶ A weakness has been identified in langflow-ai langflow up to 1.9.3. langflow contains a code injection vulnerability in validate-post_validate_code-a-real-authenticated-http-post-to-api-v1 (src/backend/base/langflow/api/v1/validate.py:13). An authenticated attacker can execute arbitrary Python code on the server by submitting malicious code to the /api/v1/validate/code endpoint, which directly executes user-supplied code without sandboxing or security controls.

The advisory is available at github.com. This vulnerability was named CVE-2026-51886 since 06/08/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/02/2026). This vulnerability is assigned to T1059 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• langflow-ai

Name

• Langflow

Version

• 1.9.0
• 1.9.1
• 1.9.2
• 1.9.3

Website

• Product: https://github.com/langflow-ai/langflow/

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