Vulnerability 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
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Langchain | Langchain.Js | < 0.3.37 |
| Langchain | Langchain\/Core | < 0.3.80 |
Related Weaknesses (CWE)
References
- https://github.com/langchain-ai/langchainjs/commit/e5063f9c6e9989ea067dfdff39262Patch
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcore%401Release Notes
- https://github.com/langchain-ai/langchainjs/releases/tag/langchain%401.2.3Release Notes
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-vVendor Advisory
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-r399-636x-vVendor Advisory
FAQ
What is CVE-2025-68665?
CVE-2025-68665 is a vulnerability with a CVSS score of 8.6 (HIGH). 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 vulnerab...
How severe is CVE-2025-68665?
CVE-2025-68665 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-68665?
Check the references section above for vendor advisories and patch information. Affected products include: Langchain Langchain.Js, Langchain Langchain\/Core.