CVE-2026-39424

Severity CVSS v4.0:

MEDIUM

Type:

Unavailable / Other

Publication date:

14/04/2026

Last modified:

20/04/2026

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&#39;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.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 5.30 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): Low
User Interaction (UI): None
Confidentiality (VC): Low
Integrity (VI): Low
Availability (VA): Low
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

5.30

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L CVSS v3.1 Severity and Metrics:

Base Score: 4.70 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): Low
Availability (A): Low