CVE-2026-73664: FreePBX Backup

High severity, CVSS 8.6. EPSS: 0.5% chance of exploitation in the next 30 days.

FreePBX is an open source IP PBX. From 17.0.5.34 until 17.0.11, the publicKeySave AJAX endpoint in Backup.class.php accepts an authenticated administrator's SSH public key and appends it to /home/asterisk/.ssh/authorized_keys for the asterisk system user without reliably enforcing backup-only command and source restrictions. The key grants persistent shell access that can execute arbitrary commands, access FreePBX and call data, modify system files, and disrupt services. This issue is fixed in version 17.0.11.

Affected products

• FreePBX Backup: from 17.0.5.34, before 17.0.11 (fixed in 17.0.11)

Published 2026-08-13. Last modified 2026-09-18.