CVE-2025-68664

LangChain serialization injection vulnerability enables secret extraction in dumps/loads APIs

State
Published
Severity
9.3 Critical
Published
Dec 23, 2025
Updated
Dec 24, 2025
Reserved
Dec 22, 2025

Read the record on cve.org

Description

LangChain is a framework for building agents and LLM-powered applications. Prior to versions 0.3.81 and 1.2.5, a serialization injection vulnerability exists in LangChain's dumps() and dumpd() functions. The functions do not escape dictionaries with 'lc' keys when serializing free-form dictionaries. 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 versions 0.3.81 and 1.2.5.

Scores

CVSSScoreVectorSource
3.19.3 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:NGitHub_M

Weaknesses

  • CWE-502 Deserialization of Untrusted Data

Affected Products

ProductVersions
langchainlangchain-ai
  • >= 1.0.0, < 1.2.5Affected
  • < 0.3.81Affected

References

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