Auth bypass in Collaboraonline Online

CVE-2026-23623

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23623: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Collaboraonline Online — versions Collabora Online < 25.04.7.5, Collabora Online < 24.04.17.3, Collabora Online < 23.05.20.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23623?
CVE-2026-23623 is a medium-severity vulnerability in Collaboraonline Online, classified under Improper Authorization. CVSS score: 5.3/10. Published 2026-02-06.
How severe is CVE-2026-23623?
Medium severity. CVSS v3 base score is 5.3 out of 10.