Missing Authorization in Group Office - #VU164345
Published: November 10, 2026
Vulnerability identifier: #VU164345
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-862
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to create or overwrite files in shared Group Office folders despite having only read permission.
The vulnerability exists due to missing write authorization in MessageController::actionSaveAttachment when saving email attachments into a selected folder using raw filesystem operations. A remote user can submit a saveAttachment request specifying a read-only folder and either an email attachment or a controlled temporary file to write unauthorized content into that folder.
Affected software
Group Office
Remediation
Install security update from vendor's website.
Group Office - addressed in versions 6.8.181, 26.0.58