PYSEC-2026-2564 LangChain vulnerable to unsafe deserialization of attacker-controlled objects through overly broad `load()` allowlists

LangChain contains older runtime code paths that deserialize run inputs, run outputs, or other application-controlled payloads using overly broad object allowlists. These paths may call load with allowedobjects="all". This does not enable arbitrary Python object deserialization, but it does allow...