MaxKB, an open-source AI assistant for enterprise, versions 2.7.1 and below contain a vulnerability in the chat export feature accessed via the /admin/api/workspace/{workspace_id}/application/{application_id}/chat/export endpoint. The vulnerability involves improper neutralization of formula elements in CSV files, where strings beginning with formula characters are exported without sanitization. This allows an attacker to craft malicious content that, when opened in spreadsheet applications like Microsoft Excel, can trigger arbitrary code execution through Dynamic Data Exchange (DDE). This vulnerability is related to CVE-2025-4546 but affects a different export sink. The issue is resolved in version 2.8.0.

An attacker who can influence the chat content that an administrator exports can embed malicious formula elements in the exported CSV file. When the administrator opens this file in Excel or similar spreadsheet software, it may execute arbitrary code via DDE, potentially compromising the administrator's workstation. The vulnerability requires no user interaction beyond opening the exported file and does not require elevated privileges to exploit. The CVSS 4.0 base score is 5.3, indicating medium severity.

This vulnerability has been fixed in MaxKB version 2.8.0. Administrators and users should upgrade to version 2.8.0 or later to remediate this issue. Until the upgrade, avoid opening exported chat history files in spreadsheet applications without proper sanitization or use alternative export methods that do not allow formula injection. Patch status is not explicitly stated in vendor advisory content but the fix is confirmed in version 2.8.0.