Sophos has disclosed a critical remote code execution vulnerability in its legacy security gateway product Sophos UTM. The flaw, identified as CVE-2026-118633, was reported through the vendor’s bug bounty program and received a CVSS v4.0 base score of 9.2, placing it in the highest severity category of Critical.
The vulnerability resides in the email proxy component when the scanning function is enabled. By sending repeated requests over several minutes, an attacker can induce a processing race condition that bypasses authentication and grants the ability to execute arbitrary commands with root privileges.
All versions of Sophos UTM are affected. Although a corrective patch has been prepared, automatic delivery is unavailable because the product has reached end-of-life status. Administrators must therefore download and install the update manually.
Sophos advises organizations that rely on the mail protection features to apply the patch without delay. The company also encourages migration to the actively supported Sophos Firewall product line to maintain ongoing security updates and vendor assistance.


