Is there a public exploit for CVE-2025-68665?

No public exploit for CVE-2025-68665 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2025-68665?

CVE-2025-68665 scores CVSS 9.1 (v3.1), rated critical. EPSS puts the chance of exploitation in the next 30 days at 0.79%.

What does CVE-2025-68665 affect?

CVE-2025-68665 affects langchain-ai @langchain/core, langchain. It is part of the AI and agent stack (LangChain).

9.1 Critical

LangChain is a framework for building LLM-powered applications.

CVE-2025-68665

Context 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. Attack surface The core vulnerability was in Serializable.toJSON(): this method failed to escape user-controlled objects containing 'lc' keys within kwargs (e.g., additionalkwargs, metadata, responsemetadata). When this unescaped data was later deserialized via load(), the injected structures were treated as legitimate LangChain objects rather than plain user data. This escaping bug enabled several attack vectors: 1. Injection via user data: Malicious LangChain object structures could be injected through user-controlled fields like metadata, additionalkwargs, or responsemetadata 2. Secret extraction: Injected secret structures could extract environment variables when secretsFromEnv was enabled (which had no…

Part of the AI stack

This affects LangChain, in Agent frameworks.

Assessment

CVSS: 9.1 (v3.1)
Severity: Critical
EPSS: 0.79% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 23 December 2025
Last updated: 19 October 2026
Affected: langchain-ai · langchainjs · @langchain/core · langchain
Weakness: CWE-502
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

At the source

References

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