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CVE-2026-20127

CRITICAL KEV CISA Exploitation: ACTIVE
10.0
CVSS 3.1
Description
A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric. 

Metadata

CVE ID
CVE-2026-20127
State
PUBLISHED
Assigner
cisco
Reserved
2025-10-08 11:59 UTC
Published
2026-02-25 16:14 UTC
Last updated
2026-06-16 17:57 UTC
Primary CWE
CWE-287
Improper Authentication
Vendor / Product
Cisco / Cisco Catalyst SD-WAN Manager
Sources
cve.org  ·  NVD

Severity & Metrics

10.0 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
ACTIVE
Automatable
yes
Tech. Impact
total
CISA Known Exploited Vulnerability
Vulnerability name
Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability
Vendor
Cisco
Product
Catalyst SD-WAN Controller and Manager
Added to KEV
2026-02-25
Due date
2026-02-27
Ransomware
Not known
Required action
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.
CISA description
Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, contain an authentication bypass vulnerability could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.
Affected products (1)
VendorProductPlatformVersions
Cisco Cisco Catalyst SD-WAN Manager — 20.1.12, 19.2.1, 18.4.4, 18.4.5 …
Weakness (CWE)
CWESourceDescription
CWE-287 cna Improper Authentication
CVSS scores (1)
ScoreSeverityVersionSourceVector
10.0 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
References (1)
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