CVE-2026-44843: Langchain

High severity, CVSS 8.2. EPSS: 0.4% chance of exploitation in the next 30 days.

LangChain is a framework for building agents and LLM-powered applications. Prior to 0.3.85 and 1.3.3, 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 allowed_objects="all". This does not enable arbitrary Python object deserialization, but it does allow any trusted LangChain-serializable object to be revived, which is broader than these runtime paths require. As a result, attacker-supplied LangChain serialized constructor dictionaries may cause trusted runtime paths to instantiate classes with untrusted constructor arguments. This vulnerability is fixed in 0.3.85 and 1.3.3.

Affected products

• Langchain Langchain: before 0.3.85 (fixed in 0.3.85); from 1.0.0, before 1.3.3 (fixed in 1.3.3)

Published 2026-05-26. Last modified 2026-07-24.