Path traversal in LangChain - CVE-2026-34070
Published: April 9, 2026 / Updated: April 20, 2026
Vulnerability identifier: #VU125664
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-34070
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to path traversal in legacy load_prompt functions in langchain_core.prompts.loading when processing user-influenced deserialized prompt configuration dictionaries. A remote attacker can supply a crafted configuration with traversal sequences or absolute paths to disclose sensitive information.
The issue is constrained by file-extension checks that limit readable files to .txt, .json, .yaml, and .yml.
Affected software
LangChain
IBM Watson Speech Services Cartridge for IBM Cloud Pak for Data
IBM Watson Speech Services Cartridge for IBM Cloud Pak for Data
How to mitigate CVE-2026-34070
Install security update from vendor's website.
LangChain - update to 1.2.22
IBM Watson Speech Services Cartridge for IBM Cloud Pak for Data - update to 5.3.1 Patch 5
IBM Watson Speech Services Cartridge for IBM Cloud Pak for Data - update to 5.3.1 Patch 5