CVE-2026-76519 Cisco Secure Email Gateway: file path flaw
In plain words: The program can be tricked into reading or writing files outside the folder it should stay in. Leaks files such as passwords and settings, or overwrites important ones.
Confirmed exploited by CISA on · US federal patch deadline Oct 17, 2026
What to do
- Install Cisco's security update for Secure Email Gateway. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Patch edge devices first — attackers often start scanning for them within hours of a fix.
- Never expose the device's admin page to the internet.
- After patching a device that was exposed, follow the vendor's compromise checks, end active sessions and change passwords.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: They face the internet and guard the whole network, so a flaw here can hand attackers a way in — and these devices usually run no antivirus, so break-ins go unnoticed.
The details
- Official name
- Cisco Secure Email Gateway Relative Path Traversal Vulnerability
- Product
- Cisco Secure Email Gateway
- CISA description
- Cisco Secure Email Gateway contains a relative path traversal vulnerability that could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system.
- Type of flaw
- File path flaw (CWE-23)
- Confirmed exploited
- Oct 14, 2026
- US federal patch deadline
- Oct 17, 2026
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Answering about CVE-2026-76519 ·
Questions about CVE-2026-76519
Is CVE-2026-76519 being exploited?
Yes. CISA added CVE-2026-76519 to its Known Exploited Vulnerabilities catalog on Oct 14, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-76519?
Install Cisco's security update for Secure Email Gateway. If no update exists, follow the vendor's workaround or stop using the product until one ships. Patch edge devices first — attackers often start scanning for them within hours of a fix.
Am I affected by CVE-2026-76519?
Only if you use Cisco Secure Email Gateway. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.