Cisco Systems has published security updates for Cisco Secure Email Gateway addressing a critical vulnerability that is already being exploited in the wild.
The flaw, identified as CVE-2026-76461, is an SQL injection issue caused by insufficient input validation in the email parsing process. Attackers can send specially crafted emails that trigger unauthenticated remote execution of arbitrary SQL commands.
According to Cisco, successful exploitation grants attackers root privileges on the underlying operating system, allowing them to run any commands on the affected appliance. The vulnerability received a CVSSv3.1 base score of 9.8 and is rated Critical.
Cisco confirmed exploitation of CVE-2026-76461 in September 2026. The company strongly recommends immediate migration to the fixed releases Cisco Secure Email Gateway 16.5.0-780, 16.0.4-3021, or 15.5.5-0141, with 16.5.0-780 being the preferred target. The 16.5.0-780 branch also contains additional fixes beyond this CVE.
Administrators are advised to review the release notes for their specific branch, as the exact fixed versions differ across maintenance streams.


