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
History

Thu, 25 Dec 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Wed, 24 Dec 2025 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 24 Dec 2025 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Langchain-ai
Langchain-ai langchainjs
Vendors & Products Langchain-ai
Langchain-ai langchainjs

Tue, 23 Dec 2025 23:15:00 +0000

Type Values Removed Values Added
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
Title LangChain serialization injection vulnerability enables secret extraction
Weaknesses CWE-502
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-12-23T22:56:04.837Z

Updated: 2025-12-24T14:38:40.268Z

Reserved: 2025-12-22T23:28:02.917Z

Link: CVE-2025-68665

cve-icon Vulnrichment

Updated: 2025-12-24T14:38:27.420Z

cve-icon NVD

Status : Received

Published: 2025-12-23T23:15:45.097

Modified: 2025-12-24T15:16:02.797

Link: CVE-2025-68665

cve-icon Redhat

Severity : Important

Publid Date: 2025-12-23T22:56:04Z

Links: CVE-2025-68665 - Bugzilla