LangGrinch -- LangChain Core Serialization Injection (CVE-2025-68664)
Date: 2025-12
Affected: LangGrinch
Attack vector: rce
Category: real-world
Severity: Critical
CVE: CVE-2025-68664
CWE: CWE-502
CVSS:  (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N)

CVSS 9.3 serialization injection in langchain-core's dumps()/loads() functions. Prompt injection could generate outputs with LangChain's internal marker key, leading to total environment variable theft (cloud creds, DB connection strings, LLM API keys), class instantiation in trusted namespaces, and potential RCE via Jinja2 templates. All langchain-core < 0.3.81 affected.


Mitigations:

Architectural layers (MAESTRO):