Authorization bypass through user-controlled key in Group Office - CVE-2026-125388
Published: November 10, 2026 / Updated: November 10, 2026
Vulnerability identifier: #VU164333
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-125388
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose all public-form submissions, including names, emails, and free-text answers, regardless of granted module access.
The vulnerability exists due to missing authorization checks in the Group-Office business/forms downloadReport() handler when exporting reports using user-controlled form IDs. A remote user can request api/download.php?blob=business/forms/report/1 and iterate sequential form IDs to download XLSX reports containing submissions from forms they are not authorized to access.
Affected software
Group Office
How to mitigate CVE-2026-125388
Install security update from vendor's website.
Group Office - addressed in versions 6.8.181, 26.0.58