CVE intelligence and bounded remediation

CVE-2026-45551 — Group-Office is an enterprise customer relationship management and groupware tool

Medium CVSS 5.1

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.

Severity
Medium
CVSS
5.1 (4.0)
Published
2026-05-29
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79, CWE-639

Affected products

No browser-safe affected-product rows are available.

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

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Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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