CVE-2026-40521 HIGH

CVE-2026-40521: FrontAccounting < 2.4.20 Path Traversal RCE via attachment upload

Vendor Frontaccounting
Product FrontAccounting
Weakness CWE-22 · Path traversal
Published June 29, 2026
Last update June 30, 2026

CVSS base score

8.7/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

FrontAccounting before 2.4.20 contains a path traversal vulnerability in the attachment upload handler that allows authenticated attackers to execute arbitrary code by uploading files with traversal sequences in the unique_name parameter. Attackers can supply path traversal sequences ../../../shell.php to write files outside the intended attachments directory into the web root, and by uploading PHP files without extension validation, achieve remote code execution as the web server user.

Key dates

02Disclosure timeline

June 29, 2026 CVE published
June 30, 2026 Record updated