langgraph-api implements the LangGraph API for rapid development and testing. From 0.1.2 until 0.15.0, JavaScript or TypeScript custom authentication Store authorization handlers can return a rewritten namespace that is not carried across the runtime boundary and applied before the Store operation. An authenticated user can therefore access another user's Store namespace when a deployment relies on namespace rewriting for isolation, allowing unauthorized reads, overwrites, searches, or deletions. Python custom authentication and handlers that reject unauthorized namespaces instead of rewriting them are not affected. This issue is fixed in version 0.15.0.