What is CVE-2026-20129?
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.
The record classifies CVE-2026-20129 under weakness class CWE-287. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 245 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 0.7% probability of exploitation in the next 30 days, higher than 53.4% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-02-25, last modified 2026-03-20
Is CVE-2026-20129 being exploited?
Weaponised exploit code for CVE-2026-20129 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 26 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- Cisco: Catalyst Sd-wan Manager, Catalyst Sd-wan Manager 20.12.6
How to fix CVE-2026-20129
The record marks a vendor fix as available for CVE-2026-20129. Vendor advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-authbp-qwCX8D4v. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-20129
1 tracked threat in the Threadlinqs corpus references CVE-2026-20129, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .