CVE-2026-34070: Langchain Core

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

LangChain is a framework for building agents and LLM-powered applications. Prior to version 1.2.22, multiple functions in langchain_core.prompts.loading read files from paths embedded in deserialized config dicts without validating against directory traversal or absolute path injection. When an application passes user-influenced prompt configurations to load_prompt() or load_prompt_from_config(), an attacker can read arbitrary files on the host filesystem, constrained only by file-extension checks (.txt for templates, .json/.yaml for examples). This issue has been patched in version 1.2.22.

Affected products

• Langchain Langchain Core: before 1.2.22 (fixed in 1.2.22)

Published 2026-03-31. Last modified 2026-08-25.