External Control of File Name or Path in Group Office - #VU164347
Published: November 10, 2026
Vulnerability identifier: #VU164347
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-73
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to overwrite other users' files within file_storage_path, cause persistent CSS injection, and potentially execute stored cross-site scripting.
The vulnerability exists due to externally controlled file paths and missing authorization in Group Office's email saveToFile action when saving messages through the raw filesystem class. A remote user can submit save_to_path with email-module access to overwrite storage files with attacker-controlled MIME messages, including customcss/style.css or customcss/javascript.js rendered globally, although MIME headers may prevent JavaScript execution.
Affected software
Group Office
Remediation
Install security update from vendor's website.
Group Office - addressed in versions 6.8.181, 26.0.58