CVE-2025-64439Public exploitNetwork attack vector

Authenticated code execution via unrestricted constructor deserialization

Published Nov 7, 2025 · Updated Nov 7, 2025

Remote code execution in LangChain LangGraph before 3.0.0 allows remote authenticated users to execute Python code via crafted checkpoints. JsonPlusSerializer's JSON reviver accepts lc=2 constructor records and resolves their id paths to arbitrary callables instead of restricting allowed types. Exploitation requires an application to persist attacker-supplied checkpoint data in JSON mode, reached explicitly or after MessagePack rejects an illegal Unicode surrogate.

CVSS severity7.4
High
EPSS probability0.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in LangChain LangGraph before 3.0.0 allows remote authenticated users to execute Python code via crafted checkpoints. JsonPlusSerializer's JSON reviver accepts lc=2 constructor records and resolves their id paths to arbitrary callables instead of restricting allowed types. Exploitation requires an application to persist attacker-supplied checkpoint data in JSON mode, reached explicitly or after MessagePack rejects an illegal Unicode surrogate.

The record

CVE
CVE-2025-64439
Published
Nov 7, 2025
Updated
Nov 7, 2025
Vendor
LangChain
Product
LangGraph
Classifications
CWE-502, CAPEC-586, T1059.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

LangChain · LangGraphversion=< 3.0.0

Published CVSS scores

7.4GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection
T1059.006Python

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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