CVE-2026-20128 Cisco Catalyst SD-WAN Manager Storing Passwords in a Recoverable Format Vulnerability
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.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 20 Apr 2026.
- Rated High severity (CVSS 7.5, scored by Vendor).
- It has been in the catalogue for 200 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
A vulnerability in the Data Collection Agent (DCA) feature of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to gain DCA user privileges on an affected system. This vulnerability is due to the presence of a credential file for the DCA user on an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request and reading the file that contains the DCA password from that affected system. A successful exploit could allow the attacker to access another affected system and gain DCA user privileges. Note: Cisco Catalyst SD-WAN Manager releases 20.18 and later are not affected by this vulnerability.
Affected Versions
| Product | Versions |
|---|---|
| Cisco Cisco Catalyst SD-WAN Manager | 20.1.12 19.2.1 18.4.4 18.4.5 20.1.1.1 20.1.1 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Cisco Catalyst SD-WAN Manager. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2026-20128 and every other exploited flaw on the list.
Sources
- CISA Known Exploited Vulnerabilities catalogue
- NVD: CVE-2026-20128
- CVE record: CVE-2026-20128
- FIRST EPSS
- cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd
- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-authbp-qwCX8D4v
