CVE-2026-20128 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 Apr 23, 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 Storing Passwords in a Recoverable Format Vulnerability
- Product
- Cisco Catalyst SD-WAN Manager
- CISA description
- Cisco Catalyst SD-WAN Manager contains a storing passwords in a recoverable format vulnerability that allows an authenticated, local attacker to gain DCA user privileges by accessing a credential file for the DCA user on the filesystem as a low-privileged user.
- Type of flaw
- Software flaw (CWE-257)
- Confirmed exploited
- Apr 20, 2026
- US federal patch deadline
- Apr 23, 2026
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Answering about CVE-2026-20128 ·
Questions about CVE-2026-20128
Is CVE-2026-20128 being exploited?
Yes. CISA added CVE-2026-20128 to its Known Exploited Vulnerabilities catalog on Apr 20, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-20128?
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-2026-20128?
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.