Critical Cisco Secure Email Gateway zero-day gives attackers root access
Actively exploited Cisco Secure Email Gateway zero-day CVE-2026-76461 lets crafted emails trigger SQL injection and root command execution; CISA added it to KEV.
Cisco released emergency patches for CVE-2026-76461, a critical SQL injection in Secure Email Gateway (physical and virtual) caused by insufficient validation in email parsing. Sending a crafted email with malicious SQL statements can yield arbitrary command execution with root privileges. Cisco was aware of active exploitation before the fixes, and CISA added the flaw to its KEV catalog; patched AsyncOS releases are 15.5.5-0141, 16.0.4-3021, and 16.5.0-780. Because successful exploits grant root, Cisco warns logs may be tampered with and advises checking external firewall/network logs and rebuilding virtual appliances with rotated credentials.