Cisco Secure Email Gateway Relative Path Traversal Vulnerability
A relative path traversal vulnerability (CVE-2026-76519) has been identified in Cisco Secure Email Gateway, allowing an unauthenticated, remote attacker to write arbitrary files on the underlying operating system. This vulnerability is listed in the CISA KEV catalog and is actively being exploited in the wild.
Summary: A relative path traversal vulnerability (CVE-2026-76519) has been identified in Cisco Secure Email Gateway, allowing an unauthenticated, remote attacker to write arbitrary files on the underlying operating system. This vulnerability is listed in the CISA KEV catalog and is actively being exploited in the wild.
This news announces a relative path traversal vulnerability (CVE-2026-76519) affecting Cisco Secure Email Gateway products, listed in the CISA KEV catalog. This vulnerability allows an unauthenticated, remote attacker to write arbitrary files on the underlying operating system of the device. This could severely compromise the integrity of the system.
A relative path traversal vulnerability occurs when an application fails to properly validate or sanitize user-supplied file paths. An attacker can use directory traversal characters like ../ to escape the directories the application is supposed to access or write to, allowing them to write files anywhere on the system. This is often used in attacks to place web shells outside the web server’s root directory.
From a live systems and infrastructure perspective, the impact of this vulnerability can be very critical. Email gateways are one of the main entry points for an organization’s communication with the outside world and are typically located at the network perimeter. Compromising this device can be used as an initial access point to the network, leading to ransomware deployment or exfiltration of sensitive data. The ability to write arbitrary files allows an attacker to establish persistence or upload further attack tools.
Engineers using Cisco Secure Email Gateway must immediately apply the security updates released for this vulnerability. Furthermore, isolating email gateways with network segmentation, strict firewall rules, and monitoring with an intrusion prevention system (IPS) are crucial to mitigate the impact of such attacks.
🔗 Source: CISA KEV Catalog
📡 Authoritative feeds & live tracking: Radar