Cisco Secure Email Gateway Flaw Exploited in the Wild, Enables Root Command Execution
Cisco warns CVE-2026-76461 in Secure Email Gateway AsyncOS is actively exploited, letting unauthenticated attackers run root commands via crafted emails.
Cisco disclosed CVE-2026-76461, a CVSS 9.8 flaw in AsyncOS for Cisco Secure Email Gateway caused by insufficient validation in email parsing, allowing unauthenticated remote attackers to execute arbitrary SQL statements leading to root command execution. Active exploitation began in September 2026, and CISA added the flaw to its KEV catalog, requiring FCEB agencies to patch by September 17, 2026. Fixes are available in AsyncOS 15.5.5-0141, 16.0.4-302, and 16.5.0-780, with no workarounds. Cisco also contacted Secure Email Cloud customers where malicious activity was detected, and the article separately notes large-scale credential attacks on Fortinet VPN appliances generating tens of millions of authentication failures.