CVE intelligence and bounded remediation

CVE-2026-23623 — Collabora Online is a collaborative online office suite based on LibreOffice technology

Medium CVSS 5.3

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtain a local copy of a shared file. Although there are no corresponding buttons in the interface, pressing Ctrl+Shift+S initiates the file download process. This allows the user to bypass the access restrictions and leads to unauthorized data retrieval. This issue has been patched in Collabora Online Development Edition version 25.04.08.2 and Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5.

Severity
Medium
CVSS
5.3 (3.1)
Published
2026-02-06
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-285

Affected products

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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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