15 October 2026
Reference: CVE-2026-76519
1. What is being reported?
The problem lies in the Advanced Malware Protection feature of Cisco Secure Email Gateway. When enabled, it incorrectly handles email attachments, allowing attackers to write harmful files and run commands with the highest system privileges by sending a malicious email.
2. What this means in plain English
If exploited, attackers could gain full control over the email gateway system, potentially leading to data theft, disruption of email services, or further attacks within your network. This is a critical risk for any organisation relying on this email security product.
3. Could this affect a small business?
Small businesses or charities using Cisco Secure Email Gateway with the Advanced Malware Protection feature enabled could be affected. Those not using this product or feature are unlikely to be impacted. If unsure, check with your IT provider.
4. What to do now
- Contact your IT provider immediately to confirm if Cisco Secure Email Gateway is in use and if it has the vulnerable feature enabled.
- Apply any security updates or mitigations provided by Cisco as soon as possible following their official instructions.
- Review your email security settings and monitor for unusual activity or unexpected emails.
- If updates or mitigations are not available, consider discontinuing use of the affected product until a fix is provided.
5. Ask your IT provider
Can you confirm whether our Cisco Secure Email Gateway is affected by the recent critical vulnerability CVE-2026-76519, and what steps are being taken to protect us?
6. Bottom line
If you use Cisco Secure Email Gateway, act quickly to apply fixes or mitigations to prevent attackers from taking control via email.
Information based on CISA KEV, NVD, and reputable security reporting.