CVE-2025-68665

LangChain serialization injection vulnerability enables secret extraction

Published Dec 23, 2025 CVSS 3.1 · 8.6 High EPSS < 1% KEV · Not listed
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

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-r399-636x-v7f6 LangChain serialization injection vulnerability enables secret extraction
History
Type Values Removed Values Added
First Time appeared Langchain
Langchain langchain.js
Langchain langchain\/core
CPEs cpe:2.3:a:langchain:langchain.js:*:*:*:*:*:*:*:*
cpe:2.3:a:langchain:langchain\/core:*:*:*:*:*:node.js:*:*
Vendors & Products Langchain
Langchain langchain.js
Langchain langchain\/core
Type Values Removed Values Added
Metrics ssvc

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 24, 2025, 2:38 PM
Reserved
Dec 22, 2025, 11:28 PM
Status
Analyzed
Published
Dec 23, 2025, 11:15 PM
Modified
Oct 19, 2026, 10:10 PM
Severity
Important
Public date
Dec 23, 2025, 10:56 PM