CVE-2025-68665

What it is

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

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-12-23 23:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-19 22:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.8% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-12-23 23:15 UTC

Last modified

2026-10-19 22:10 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-502 · Unsafe deserialization

Record status

Analyzed

Affected

• Langchain langchain.js < 0.3.37
• Langchain langchain.js < 1.2.3
• Langchain langchain\/core < 0.3.80
• Langchain langchain\/core < 1.1.8

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-68665.md and follow it. Check whether this project is affected by CVE-2025-68665. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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