LangChain < 1.3.9 Path Traversal (CVE-2026-55443)

medium Nessus Plugin ID 322754

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Synopsis

The remote host is affected by a path traversal vulnerability.

Description

The version of LangChain installed on the remote host is prior to 1.3.9. It is, therefore, affected by a path traversal vulnerability:

- Several LangChain components that resolve filesystem paths or expand search patterns do not consistently confine the resolved path to the intended root directory. Affected behaviors include a file-search agent middleware that validates a starting directory but not the search pattern or resolved target of matched files, prompt and chain/agent-configuration loaders that accept path fields and resolve them without confining the result to a trusted base, and path-prefix authorization checks that compare by string prefix without a path-segment boundary.
When these components receive path values influenced by an untrusted source, the result can be disclosure of files outside the intended boundary. (CVE-2026-55443)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to LangChain version 1.3.9 or later.

Plugin Details

Severity: Medium

ID: 322754

File Name: langchain_CVE-2026-55443.nasl

Version: 1.3

Type: Local

Agent: windows, macosx, unix

Family: Artificial Intelligence

Published: 6/25/2026

Updated: 6/29/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.73

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:N/A:N

CVSS Score Source: CVE-2026-55443

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:langchain-ai:langchain

Required KB Items: installed_sw/LangChain

Exploit Ease: No known exploits are available

Patch Publication Date: 6/12/2026

Vulnerability Publication Date: 6/12/2026

Reference Information

CVE: CVE-2026-55443

Detections

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