PT-2026-28599 · Unknown · Langchain-Core

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CVE-2026-34070

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Published

2026-03-27

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Updated

2026-07-10

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Name of the Vulnerable Software and Affected Versions LangChain versions prior to 1.2.22
Description Multiple functions within langchain core.prompts.loading read files from paths embedded in deserialized configuration dictionaries without validating against absolute path injection or directory traversal (a technique used to access files and directories outside the intended folder). When an application passes user-influenced prompt configurations to the load prompt() or load prompt from config() endpoints, an attacker can read arbitrary files on the host filesystem. This access is limited by file-extension checks, where .txt is required for templates and .json or .yaml for examples. The affected internal functions include load template(), load examples(), and load few shot prompt(). Specifically, the template path, suffix path, and prefix path variables are processed by load template(), while the examples variable (when provided as a string) is processed by load examples(), and the example prompt path variable is processed by load few shot prompt().
Recommendations Update LangChain to version 1.2.22 or later. As a temporary mitigation, avoid using the load prompt() and load prompt from config() functions with untrusted user input. Migrate from the deprecated legacy APIs to the dumpd, dumps, load, and loads serialization APIs in langchain core.load.

Exploit

Fix

Path traversal

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Weakness Enumeration

Related Identifiers

CVE-2026-34070
ECHO-34C7-CA18-1A8C
GHSA-QH6H-P6C9-FF54
PYSEC-2026-2193

Affected Products

Langchain-Core