Cisco Secure Email Gateway vulnerability (CVE-2026-76461) in active exploitation

Threat Research advisory vulnerability Cisco

On September 14, 2026, Cisco disclosed a vulnerability in Cisco Secure Email Gateway. CVE-2026-76461 is a critical (CVSS score of 9.8) SQL injection flaw in the email parsing functionality of Cisco AsyncOS Software. Successful exploitation “could allow an unauthenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system.” Cisco confirmed exploitation of the vulnerability in the wild, and the U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added it to the Known Exploited Vulnerabilities (KEV) catalog.

Recommended actions

Counter Threat Unit™ (CTU) researchers recommend that organizations identify vulnerable versions of Cisco AsyncOS for Cisco Secure Email Gateway in their environments and upgrade as appropriate.

Sophos countermeasures

SophosLabs continues to monitor the threat landscape for activity related to this vulnerability and will deliver detections and protections as available.

About the Author(s)

Sophos Counter Threat Unit Research Team

Sophos Counter Threat Unit™ (CTU) researchers are recognized authorities in the cybersecurity field, regularly contributing expert analysis to global media, publishing technical analyses for the security community, and presenting about emerging threats at leading security conferences. Backed by Sophos’ advanced security technologies and a broad network of intelligence contacts and partners, the CTU™ plays a critical role in identifying and tracking threat actors and analyzing anomalous activity, uncovering new attack techniques, threats, and major shifts in the threat landscape.