LangChain is a framework for building agents and LLM-powered applications. Prior to versions 0.3.81 and 1.2.5, a serialization injection vulnerability exists in LangChain's dumps() and dumpd() functions. The functions do not escape dictionaries with 'lc' keys when serializing free-form dictionaries. The 'lc' key is used internally by LangChain to mark serialized objects. When user-controlled data contains this key structure, it is treated as a legitimate LangChain object during deserialization rather than plain user data. This issue has been patched in versions 0.3.81 and 1.2.5.
https://github.com/langchain-ai/langchain/security/advisories/GHSA-c67j-w6g6-q2cm
https://github.com/langchain-ai/langchain/releases/tag/langchain-core%3D%3D1.2.5
https://github.com/langchain-ai/langchain/releases/tag/langchain-core%3D%3D0.3.81
https://github.com/langchain-ai/langchain/pull/34458
https://github.com/langchain-ai/langchain/pull/34455
https://github.com/langchain-ai/langchain/commit/d9ec4c5cc78960abd37da79b0250f5642e6f0ce6
https://github.com/langchain-ai/langchain/commit/5ec0fa69de31bbe3d76e4cf9cd65a6accb8466c8