Cisco Catalyst SD-WAN Manager: Improper Authentication
CVE-2026-20129 is a critical-severity improper authentication vulnerability in Cisco Catalyst SD-WAN Manager from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Catalyst SD-WAN Manager versions: 20.1.12; 19.2.1; 18.4.4, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.81% chance of exploitation within 30 days, higher than 58% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Catalyst Sd-wan Manager to 20.9.8.2 or 20.12.5.3 or 20.15.4.2 or 20.18, whichever matches your release line, or a later version.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| 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; 19.3.0; 19.2.2; and 32 more ranges | Not stated |
| Cisco | Catalyst Sd-wan Manager | before 20.9.8.2; 20.11 up to, but not including, 20.12.5.3; 20.13 up to, but not including, 20.15.4.2; 20.16 up to, but not including, 20.18; 20.12.6 | 20.9.8.2, 20.12.5.3, 20.15.4.2, 20.18 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
A vulnerability in the API user authentication of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to gain access to an affected system as a user who has the netadmin role. The vulnerability is due to improper authentication for requests that are sent to the API. An attacker could exploit this vulnerability by sending a crafted request to the API of an affected system. A successful exploit could allow the attacker to execute commands with the privileges of the netadmin role. Note: Cisco Catalyst SD-WAN Manager releases 20.18 and later are not affected by this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco Catalyst SD-WAN Manager
- 9.8 Critical severity
- 7.7 High severity
- 8.8 High severity
- 9.1 Critical severity
- 9.9 Critical severity
- 9.9 Critical severity
Recent Improper Authentication vulnerabilities
- 10.0 Critical severity
- 7.5 High severity
- 9.1 Critical severity
- 8.1 High severity
- 9.4 Critical severity
- 10.0 Critical severity
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