CVE-2023-39659Public exploitNetwork attack vector

Remote code execution via unchecked agent prompt

Published Aug 15, 2023 · Updated Oct 8, 2024

Code injection in LangChain before 0.0.325 allows remote attackers to execute arbitrary Python code through a crafted agent prompt. PythonAstREPLTool._run passes model-selected prompt content to Python execution without sanitizing or restricting dangerous operations. Exposure requires an application that accepts attacker-controlled prompts and equips its agent with the Python REPL tool; successful exploitation runs commands with the host process's permissions.

CVSS severity9.8
Critical
EPSS probability1.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in LangChain before 0.0.325 allows remote attackers to execute arbitrary Python code through a crafted agent prompt. PythonAstREPLTool._run passes model-selected prompt content to Python execution without sanitizing or restricting dangerous operations. Exposure requires an application that accepts attacker-controlled prompts and equips its agent with the Python REPL tool; successful exploitation runs commands with the host process's permissions.

The record

CVE
CVE-2023-39659
Published
Aug 15, 2023
Updated
Oct 8, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-74, T1059.006
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('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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