CVE-2026-48776 Details

A vulnerability exists in the LangGraph Python SDK in versions through 0.3.14, allowing for unsafe URL path construction. This issue arises from unsanitized, caller-supplied identifier values used in HTTP request paths for resource operations. In scenarios where the SDK receives identifier values from untrusted sources, this could lead to unintended access, modification, or deletion of resources beyond the user's authorized scope. The vulnerability is particularly critical in deployments that forward end-user-supplied values directly into SDK identifier parameters without proper validation, and rely on URL-prefix-based authorization at an upstream layer, where the authorization decision is based on the intended path rather than the final delivered request path.

Users should upgrade to LangGraph SDK version 0.3.15 or later, which fixes the vulnerability by applying path-segment encoding to identifier values before they are added to request URL templates. This ensures that characters with special meaning in URL paths are transmitted as encoded byte sequences, directing requests to the correct resources. Additionally, it is recommended to validate identifier values at the point where untrusted input is received, before passing them to SDK methods. For deployments with URL-prefix-based authorization upstream, consider shifting authorization to the LangGraph server layer or on validated request paths.