Vulnerability in Libreoffice

CVE-2021-25635

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.

Vulnerability class: Improper Certificate Validation

EPSS: 0.001 (3.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-25635?
CVE-2021-25635 is a medium-severity vulnerability in Libreoffice, classified under Improper Certificate Validation. CVSS score: 5.5/10. Published 2025-03-21.
How severe is CVE-2021-25635?
Medium severity. CVSS v3 base score is 5.5 out of 10.