CVE-2025-68665: LangChain is a framework for building LLM-powered applications. Prior to @langchain/core versions 0.3.80 and 1.1.8, and

LangChain, a framework for building applications powered by LLMs (large language models), had a serialization injection vulnerability (a flaw where specially crafted data can be misinterpreted as legitimate code during the conversion of objects to JSON format) in its toJSON() method. The vulnerability occurred because the method failed to properly escape objects containing 'lc' keys, which LangChain uses internally to mark serialized objects, allowing attackers to trick the system into treating malicious user data as legitimate LangChain objects when deserializing (converting back from JSON format).