GHSA-pjwx-r37v-7724: LangChain vulnerable to unsafe deserialization of attacker-controlled objects through overly broad `load()` allowlists

Summary

LangChain's older runtime code paths deserialize run inputs, run outputs, and other application-controlled payloads using overly broad allowlists, sometimes calling `load()` with `allowed_objects="all"`. Attacker-supplied LangChain serialized constructor dictionaries can therefore cause trusted classes to be instantiated with untrusted constructor arguments, when the application accepts untrusted structured input and preserves it in run data. A related `_is_lc_secret` validation bypass in the serialization layer provides an additional path to the same revival logic.

Mitigation

LangChain will deprecate `RunnableWithMessageHistory`, `astream_log()` and `astream_events(version="v1")`, and applications should migrate to the currently recommended APIs, including the `stream` API. LangChain will also update `load()` and `loads()` to tighten deserialization so broad object revival is not applied implicitly to untrusted or application-controlled payloads.

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

• langchain-corePyPILLM dependency since 2023-11-20 · 60 tracked dependents

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