CVE-2026-45551
CWE-79Published: May 29, 2026· Updated: May 29, 2026
Official Description
Group-Office is an enterprise customer relationship management and groupware tool. Prior to 26.0.25, 25.0.100, and 6.8.165, GroupOffice allows authenticated users to persist arbitrary legacy settings for any user_id via index.php?r=core/saveSetting. A separate client-side sink in the email module injects the email_font_size setting directly into JavaScript without escaping. By combining these two issues, any low-privileged authenticated user can overwrite an administrator's email_font_size setting with a JavaScript payload and trigger stored XSS in the administrator's browser when the GroupOffice web client loads views/Extjs3/modulescripts.php. This vulnerability is fixed in 26.0.25, 25.0.100, and 6.8.165.
Technical Analysis
CVE-2026-45551 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-45551 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts