CVE-2026-39424: MaxKB has CSV Injection in its Application Chat Export Functionality

Vulnerability summary

CVE-2026-39424 is a medium (CVSS 5.3) vulnerability in 1panel-dev maxkb. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 30.7% of scored vulnerabilities.

Timeline

1. 14-04-2026
   PublishedVulnerability first disclosed.
2. 16-04-2026
   Last modifiedVulnerability information updated.

Description

MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, the chat export feature is vulnerable to Improper Neutralization of Formula Elements in a CSV File. When an administrator exports the application chat history to an Excel file (.xlsx) via the /admin/api/workspace/{workspace_id}/application/{application_id}/chat/export endpoint, strings starting with formula characters are written directly without proper sanitization. Opening this file in spreadsheet applications like Microsoft Excel can lead to Arbitrary Code Execution (RCE) on the administrator's workstation via Dynamic Data Exchange (DDE). The issue is a variant of CVE-2025-4546, which fixed the exact same pattern in apps/dataset/serializers/document_serializers.py but missed the application chat export sink. This issue has been fixed in version 2.8.0.

• CWE-1236Improper Neutralization of Formula Elements in a CSV FileThe product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product.