Cisco Secure Email Gateway zero-day CVE-2026-76519 allows unauthenticated root RCE via malicious email, exploited in the wild
Cisco disclosed that CVE-2026-76519, a critical (CVSS 9.8) flaw in Secure Email Gateway (SEG), has been exploited as a zero-day before a fix was available. A remote, unauthenticated attacker can write files and execute commands as root on the appliance simply by sending a malicious email. CISA added the flaw to its Known Exploited Vulnera…