Deserialization in Langchain Langchain\/core
CVE-2025-68665
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
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.008 (54.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: -0.000
Affected products
- Langchain Langchain\/core
- Langchain Langchain.js
- Langchain-Ai Langchainjs — versions @langchain/core >= 1.0.0, < 1.1.8, @langchain/core < 0.3.80, langchain >= 1.0.0, < 1.2.3
Weakness classification (CWE)
References
- github.com/langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-v7f6 (Vendor Advisory)
- github.com/langchain-ai/langchainjs/commit/e5063f9c6e9989ea067dfdff39262b9e7b6a… (Patch)
- github.com/langchain-ai/langchainjs/releases/tag/@langchain/core@1.1.8 (Release Notes)
- github.com/langchain-ai/langchainjs/releases/tag/langchain@1.2.3 (Release Notes)
Frequently asked questions
- What is CVE-2025-68665?
- CVE-2025-68665 is a high-severity vulnerability in Langchain Langchain\/core, classified under Deserialization of Untrusted Data. CVSS score: 8.6/10. Published 2025-12-23.
- How severe is CVE-2025-68665?
- High severity. CVSS v3 base score is 8.6 out of 10.