CVE-2026-76519: Cisco Secure Email Gateway

What is CVE-2026-76519?

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.

CVSS9.8 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWECWE-23

NVD published2026-10-14

NVD last modified2026-10-15

Timeline

2026-10-14Published to the U.S. National Vulnerability Database (NVD)
2026-10-14Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-10-15First covered in a defend.network daily briefing
2026-10-15NVD record last updated
2026-10-17CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Cisco Secure Email Gateway Relative Path Traversal Vulnerability

Added to KEV2026-10-14

Federal patch deadline2026-10-17

Known ransomware useUnknown

Affected product

Cisco Secure Email Gateway

Remediation Steps

Apply the vendor security update for Cisco Secure Email Gateway as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 2 of October 2026 (October 12 – 18)
Cisco Email Gateway RCE exploited; Nextcloud backdoors; 3 phishing platforms disrupted (2026-10-15)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.