CVE-2026-20129 | Cisco Catayst SD-WAN Authentication Bypass Vulnerability

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. 

Published: 2026-02-25 Last update: 2026-03-04 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20129 is rated Moderate Risk (45.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.06%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20129

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.16% 0.06% -0.10%
2 2026-03-22 0.12% 0.16% +0.03%
3 2026-02-26 — 0.12% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20129

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-20129

Affected software / configurations for CVE-2026-20129

Vendor Product Version Raw CPE
cisco catalyst_sd-wan_manager < 20.9.8.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.11, < 20.12.5.3 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.13, < 20.15.4.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.16, < 20.18 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager 20.12.6 cpe:2.3:a:cisco:catalyst_sd-wan_manager:20.12.6:*:*:*:*:*:*:*

References for CVE-2026-20129

cvelogic Threat Intelligence