By The Hacker News
Publication Date: 2026-10-14 18:38:00
Attackers are exploiting a critical flaw in Cisco Secure Email Gateway that lets a sender with no login write files to the appliance’s operating system, Cisco said in an advisory on Wednesday.
The attacker sends an email with a crafted attachment through the gateway and, if it succeeds, could then run commands as root. The appliance filters an organization’s email for spam, malware, and other threats, and only a gateway with the File Reputation service enabled and a Content Scanner Tools package older than version 25.3.0.5525 is vulnerable.
The fix has been shipping since September 14 in AsyncOS 15.5.5-014 and 16.5.0-780, the builds Cisco listed as fixed in a hardening release that day, which the company now says covered this flaw. It also arrives as a Content Scanner Tools update, version 25.3.0.5525 or later, which installs without a software upgrade or a restart.
Cisco found the flaw, tracked as CVE-2026-76519 (CVSS score: 9.8), in its own internal security scanning and…