CVE-2026-51882

Deferred Deferred - Pending Action

BaseFortify

Publication date: 2026-10-01

Last updated on: 2026-10-07

Assigner: MITRE

Description

The OpenAI-compatible file upload endpoint `/v1/files` in Langchain-Chatchat 0.3.0 is vulnerable to path traversal. An attacker can write files to arbitrary locations outside the `openai_files` directory by crafting malicious filenames.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-01

Last Modified

2026-10-07

Generated

2026-10-19

AI Q&A

2026-10-02

EPSS Evaluated

2026-10-18

NVD

CVE-2026-51882

EUVD

EUVD-2026-91123

Affected Vendors & Products

Vendor	Product	Version / Range
n/a	n/a	n/a

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-22	The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Attack-Flow Graph

Executive Summary

The vulnerability is a path traversal issue in the OpenAI-compatible file upload endpoint `/v1/files` of Langchain-Chatchat version 0.3.0. It allows attackers to write files to any location outside the intended `openai_files` directory by manipulating filenames.

Detection Guidance

Check for unauthorized file writes outside the intended directory by monitoring file system changes. Look for suspicious filenames containing path traversal sequences like '../' in upload requests to the /v1/files endpoint.

Impact Analysis

This vulnerability could allow an attacker to overwrite critical system files, inject malicious code, or place files in sensitive directories. This may lead to remote code execution, data theft, or system compromise depending on the attacker's goals.

Compliance Impact

This vulnerability could potentially violate compliance with GDPR and HIPAA by allowing unauthorized file writes outside designated directories. Unrestricted file uploads may lead to unauthorized data storage or exposure, risking data breaches or improper data handling.

Mitigation Strategies

Disable or restrict access to the /v1/files endpoint. Implement strict input validation for filenames to block path traversal attempts. Update Langchain-Chatchat to a patched version if available.

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