CVE-2021-25832: ONLYOFFICE Document Server

Critical severity, CVSS 9.8. EPSS: 12.6% chance of exploitation in the next 30 days.

A heap buffer overflow vulnerability inside of BMP image processing was found at [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v6.0.0. Using this vulnerability, an attacker is able to gain remote code executions on DocumentServer.

Affected products

• ONLYOFFICE Document Server: from 4.0.0-9, up to and including 6.0.0

Published 2021-03-01. Last modified 2026-06-17.