CVE-2025-6704: Sophos Firewall Firmware

Critical severity, CVSS 9.8. EPSS: 9.5% chance of exploitation in the next 30 days.

An arbitrary file writing vulnerability in the Secure PDF eXchange (SPX) feature of Sophos Firewall versions older than 21.0 MR2 (21.0.2) can lead to pre-auth remote code execution, if a specific configuration of SPX is enabled in combination with the firewall running in High Availability (HA) mode.

Affected products

• Sophos Firewall Firmware: before 21.0.2 (fixed in 21.0.2)

Published 2025-07-21. Last modified 2026-06-17.