CVE intelligence and bounded remediation

CVE-2026-44843 — LangChain is a framework for building agents and LLM-powered applications

High CVSS 8.2

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.

Severity
High
CVSS
8.2 (3.1)
Published
2026-05-26
CISA KEV
Not currently listed
Ecosystem
python/pypi
Weaknesses
CWE-502

Affected products

  • langchain / langchain

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Unsafe deserialization and object reconstruction

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Check exposure

  • Inventory serialization formats accepted from requests, queues, caches, files, cookies, and cross-service messages.
  • Trace whether untrusted input can select classes, types, callbacks, constructors, or object hooks during decoding.
  • Identify signing, schema validation, trust-boundary, and compatibility settings for each decoder.

Remediate safely

  • Replace native object deserialization with a data-only format and explicit schema validation.
  • If replacement is not immediate, use a safe decoder with a minimal type allowlist and disable polymorphic or executable hooks.
  • Update the affected library and add inert tests for unknown types, extra fields, malformed nesting, and unsigned data.

Authoritative sources

Complete CVE record and remediation plan

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