CVE-2026-20127CiscoRouters and networkingFebruary 25, 2026

Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

Critical 10Actively exploited

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.

What to do

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.

Running Cisco devices? Get an email when a new vulnerability comes out. Free, unsubscribe in one click.
Turn on Cisco alerts

Details

Vendor
Cisco
Product
Cisco Catalyst SD-WAN
CVE
CVE-2026-20127
Affected versions
Cisco Catalyst SD-WAN Manager 20.1: 7 versions, from 20.1.1 to 20.1.12
Cisco Catalyst SD-WAN Manager 19.2: 14 versions, from 19.2.0 to 19.2.929
Cisco Catalyst SD-WAN Manager 18.4: 10 versions, from 18.4.0 to 18.4.501_ES
Cisco Catalyst SD-WAN Manager 19.3: 19.3.0
Cisco Catalyst SD-WAN Manager 18.3: 11 versions, from 18.3.0 to 18.3.8
Cisco Catalyst SD-WAN Manager 19.0: 19.0.0; 19.0.1a
Cisco Catalyst SD-WAN Manager 19.1: 19.1.0
Cisco Catalyst SD-WAN Manager 17.2: 7 versions, from 17.2.4 to 17.2.10
Cisco Catalyst SD-WAN Manager 18.2: 18.2.0
Cisco Catalyst SD-WAN Manager 20.3: 56 versions, from 20.3.1 to 20.3.814
Cisco Catalyst SD-WAN Manager 20.4: 20 versions, from 20.4.1 to 20.4.2.3
Cisco Catalyst SD-WAN Manager 20.5: 6 versions, from 20.5.0.1.1 to 20.5.1.2
Cisco Catalyst SD-WAN Manager 20.6: 74 versions, from 20.6.0.18.3 to 20.6.8
Cisco Catalyst SD-WAN Manager 20.7: 5 versions, from 20.7.1EFT2 to 20.7.2
Cisco Catalyst SD-WAN Manager 20.8: 20.8.1
Cisco Catalyst SD-WAN Manager 20.9: 64 versions, from 20.9.1EFT2 to 20.9.8_LI_Images
Cisco Catalyst SD-WAN Manager 20.10: 4 versions, from 20.10.1 to 20.10.1.2
Cisco Catalyst SD-WAN Manager 20.11: 4 versions, from 20.11.1 to 20.11.1.2
Cisco Catalyst SD-WAN Manager 20.12: 26 versions, from 20.12.1 to 20.12.501
Cisco Catalyst SD-WAN Manager 20.13: 20.13.1_LI_Images; 20.13.1
Cisco Catalyst SD-WAN Manager 20.14: 20.14.1; 20.14.1_LI_Images
Cisco Catalyst SD-WAN Manager 20.15: 11 versions, from 20.15.1_LI_Images to 20.15.4.1
Cisco Catalyst SD-WAN Manager 20.16: 20.16.1; 20.16.1_LI_Images
Cisco Catalyst SD-WAN Manager 20.18: 4 versions, from 20.18.1 to 20.18.2_LI_Images (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
10
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
February 27, 2026 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
February 25, 2026

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

More Cisco advisories