CVE-2021-25635: Libreoffice

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to self sign an ODF document, with a signature untrusted by the target, then modify it to change the signature algorithm to an invalid (or unknown to LibreOffice) algorithm and LibreOffice would incorrectly present such a signature with an unknown algorithm as a valid signature issued by a trusted person This issue affects LibreOffice: from 7.0 before 7.0.5, from 7.1 before 7.1.1.

Affected products

• Libreoffice Libreoffice: from 7.0.0, before 7.0.5.1 (fixed in 7.0.5.1); from 7.1.0.0, up to and including 7.1.1.1

Published 2025-03-21. Last modified 2026-06-17.