CVE-2025-68665
Severity CVSS v4.0:
Pending analysis
Type:
CWE-502
Deserialization of Untrusted Dat
Publication date:
23/12/2025
Last modified:
23/12/2025
Description
LangChain is a framework for building LLM-powered applications. Prior to @langchain/core versions 0.3.80 and 1.1.8, and prior to langchain versions 0.3.37 and 1.2.3, a serialization injection vulnerability exists in LangChain JS's toJSON() method (and subsequently when string-ifying objects using JSON.stringify(). The method did not escape objects with 'lc' keys when serializing free-form data in kwargs. 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 @langchain/core versions 0.3.80 and 1.1.8, and langchain versions 0.3.37 and 1.2.3
Impact
Base Score 3.x
8.60
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://github.com/langchain-ai/langchainjs/commit/e5063f9c6e9989ea067dfdff39262b9e7b6aba62
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcore%401.1.8
- https://github.com/langchain-ai/langchainjs/releases/tag/langchain%401.2.3
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-v7f6