CVE-2020-4020: Atlassian Companion

High severity, CVSS 7.2. EPSS: 1.7% chance of exploitation in the next 30 days.

The file downloading functionality in the Atlassian Companion App before version 1.0.0 allows remote attackers, who control a Confluence Server instance that the Companion App is connected to, execute arbitrary .exe files via a Protection Mechanism Failure.

Affected products

• Atlassian Companion: before 1.0.0 (fixed in 1.0.0)

Published 2020-06-01. Last modified 2026-06-17.