PYSEC-2026-2574 LangGraph: BaseCache Deserialization of Untrusted Data may lead to Remote Code Execution

Context A Remote Code Execution vulnerability exists in LangGraph's caching layer when applications enable cache backends that inherit from BaseCache and opt nodes into caching via CachePolicy. Prior to langgraph-checkpoint 4.0.0, BaseCache defaults to JsonPlusSerializerpicklefallback=True. When...