Root RCE Zero-Day in Cisco Secure Email Gateway Under Active Exploitation
Summary
A zero-day vulnerability, CVE-2026-76461, has been discovered in Cisco Secure Email Gateway. This unauthenticated remote code execution (RCE) vulnerability allows attackers to gain root privileges on the underlying operating system and execute arbitrary commands. The vulnerability is reportedly under active exploitation.
IFF Assessment
This vulnerability allows unauthenticated attackers to gain root access and execute arbitrary commands, posing a significant threat to organizations using Cisco Secure Email Gateway.
Severity
CISA KEV: Listed as actively exploited. Federal patch due: September 17, 2026. Known ransomware use: Unknown.
Defender Context
Organizations using Cisco Secure Email Gateway should prioritize patching or mitigating this critical vulnerability immediately. The active exploitation of this zero-day highlights the need for robust email security monitoring and rapid incident response capabilities.