CVE-2026-76504 Cisco Catalyst SD-WAN Manager: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Oct 3, 2026
What to do
- Install Cisco's security update for Catalyst SD-WAN Manager. 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 Catalyst SD-WAN Manager Hex Encoding Vulnerability
- Product
- Cisco Catalyst SD-WAN Manager
- CISA description
- Cisco Catalyst SD-WAN Manager contains a hex encoding vulnerability that could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user due to improper handling of URI encoding in an HTTP request.
- Type of flaw
- Software flaw (CWE-177)
- Confirmed exploited
- Sep 30, 2026
- US federal patch deadline
- Oct 3, 2026
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Answering about CVE-2026-76504 ·
Questions about CVE-2026-76504
Is CVE-2026-76504 being exploited?
Yes. CISA added CVE-2026-76504 to its Known Exploited Vulnerabilities catalog on Sep 30, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-76504?
Install Cisco's security update for Catalyst SD-WAN Manager. 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-2026-76504?
Only if you use Cisco Catalyst SD-WAN Manager. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.