Cisco Secure Email Gateway Vulnerability CVE-2026-76519 Added to KEV List

## Overview CISA added CVE-2026-76519 to its Known Exploited Vulnerabilities (KEV) list on October 14, 2026. This vulnerability affects Cisco Secure Email Gateway and has a CVSS score of 9.8. It enables unauthenticated remote attackers to write arbitrary files on the underlying operating system. ## Technical Details The vulnerability arises from improper handling of email attachments when the file reputation service is enabled. An attacker can exploit this by sending a specially crafted email with a malicious attachment. If the email is processed by an affected device, the attacker can write files and potentially execute commands with root privileges. ## Impact Successful exploitation of CVE-2026-76519 could lead to severe consequences, including unauthorized access to the operating system and execution of arbitrary commands. This could compromise the integrity and confidentiality of the system, making it a critical risk for organizations using the affected Cisco product. ## Mitigation Defenders should immediately update their Cisco Secure Email Gateway to the latest version that addresses this vulnerability. It is crucial to monitor email traffic for suspicious attachments and implement strict email filtering rules. Organizations should also review their security policies and ensure that all email handling features are configured securely.