CVE-2026-23623: collaboraonline online Improper Authorization

Vulnerability summary

CVE-2026-23623 is a medium (CVSS 5.3) Improper Authorization vulnerability in collaboraonline online. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 13.6% of scored vulnerabilities.

Timeline

1. 05-02-2026
   PublishedVulnerability first disclosed.
2. 06-02-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.