Actively exploited · Published Oct 14, 2026 · Assigned by cisco
CVE-2026-76519Cisco Secure Email Gateway Arbitrary File Write Vulnerability
Critical 9.8 Exploited
In plain English
A critical-severity security flaw in Cisco Secure Email from Cisco. Attackers are actively exploiting it in the wild (listed by CISA on October 14, 2026). The chance it is exploited in the next 30 days is estimated at 6.2% (higher than 94% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit. 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.
CISA guidance
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.
Federal agencies must remediate by Oct 17, 2026.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Email | 14.0.0-69813.5.1-27713.0.0-39214.2.0-62013.0.5-00713.5.4-03814.2.1-02014.3.0-032 |
Weakness: CWE-23 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H