CVE-2025-68665
LangChain serialization injection vulnerability enables secret extraction
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
- Affected
- langchain-ai · langchainjs
- CVSS v3.1 NVD
- 9.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS v3.1 GITHUB
- 8.6 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - EPSS
- 0.79% chance of exploitation in the next 30 days, 56th percentile
- Published
- 2025-12-23
- Updated
- 2025-12-24
Proof-of-concept exploits (1)
Security advisories
- langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-v7f6
- langchain-ai/langchainjs/commit/e5063f9c6e9989ea067dfdff39262b9e7b6aba62