CVE-2026-76519
Published 2026-10-14 · Updated 2026-10-14 · Source psirt@cisco.com
Summary
CVE-2026-76519 is a critical-severity (CVSS 9.8) vulnerability in Cisco Secure Email Gateway. CISA added it to the Known Exploited Vulnerabilities catalog on October 14, 2026, which means exploitation in the wild has been confirmed; US federal agencies must remediate it by October 17, 2026. CISA does not currently list it as used in ransomware campaigns. Cisco has 100 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.
All 100 known-exploited Cisco vulnerabilities →Description
A vulnerability in the Advanced Malware Protection (AMP) feature of Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system. This vulnerability is due to improper handling of email attachments when the file reputation service is enabled. An attacker could exploit this vulnerability by sending an email that contains a crafted attachment through an affected device. A successful exploit could allow the attacker to write arbitrary files and execute commands with root privileges on the underlying operating system.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Cisco — Secure Email Gateway
Name: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
Date added: 2026-10-14 · Due: 2026-10-17
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.