CVE-2026-20127
Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability
Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
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 notes
CISA Mitigation Instructions: https://www.cisa.gov/news-events/directives/ed-26-03-mitigate-vulnerabilities-cisco-sd-wan-systems ; https://www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk ; https://nvd.nist.gov/vuln/detail/CVE-2026-20127
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.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation Context
as of October 17, 2026- CISA added CVE-2026-20127 to the KEV catalog on the day its CVE record was published. The median for entries added in 2026 so far is 14 days.
- It is one of 101 Cisco entries in the CISA KEV catalog, and one of 19 added in 2026.
- Its current EPSS score (88.5%) is higher than that of 71% of CISA KEV entries.
Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| Cisco | 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 19.2.099 18.3.6 18.3.7 19.2.0 18.3.8 19.0.0 19.1.0 18.4.302 18.4.303 19.2.097 19.2.098 17.2.10 18.3.6.1 19.0.1a 18.2.0 18.4.3 18.4.1 17.2.8 18.3.3.1 18.4.0 18.3.1 17.2.6 17.2.9 18.3.4 17.2.5 18.3.1.1 18.3.5 18.4.0.1 18.3.3 17.2.7 17.2.4 18.3.0 19.2.3 18.4.501_ES 20.3.1 20.1.2 19.2.929 19.2.31 20.3.2 19.2.32 20.3.2_925 20.3.2.1 20.3.2.1_927 18.4.6 20.1.2_937 20.4.1 20.3.2_928 20.3.2_929 20.4.1.0.1 20.3.2.1_930 19.2.4 20.5.0.1.1 20.4.1.1 20.3.3 19.2.4.0.1 20.3.2_937 20.3.3.1 20.5.1 20.1.3 20.3.3.0.4 20.3.3.1.2 20.3.3.1.1 20.4.1.2 20.3.3.0.2 20.4.1.1.5 20.4.1.0.01 20.4.1.0.02 20.3.3.1.7 20.3.3.1.5 20.5.1.0.1 20.3.3.1.10 20.3.3.0.8 20.4.2 20.4.2.0.1 20.3.4 20.3.3.0.14 19.2.4.0.8 19.2.4.0.9 20.3.4.0.1 20.3.2.0.5 20.6.1 20.5.1.0.2 20.3.3.0.17 20.6.1.1 20.6.0.18.3 20.3.2.0.6 20.6.0.18.4 20.4.2.0.2 20.3.3.0.16 20.3.4.0.5 20.6.1.0.1 20.3.4.0.6 20.6.2 20.7.1EFT2 20.3.4.0.9 20.3.4.0.11 20.4.2.0.4 20.3.3.0.18 20.7.1 20.6.2.1 20.3.4.1 20.5.1.1 20.4.2.1 20.4.2.1.1 20.3.4.1.1 20.3.813 20.3.4.0.19 20.4.2.2.1 20.5.1.2 20.3.4.2 20.3.814 20.4.2.2 20.6.2.2 20.3.4.2.1 20.7.1.1 20.3.4.1.2 20.6.2.2.2 20.3.4.0.20 20.6.2.2.3 20.4.2.2.2 20.3.5 20.6.2.0.4 20.4.2.2.3 20.3.4.0.24 20.6.2.2.7 20.6.3 20.3.4.2.2 20.4.2.2.4 20.7.1.0.2 20.8.1 20.3.5.0.8 20.3.5.0.9 20.4.2.2.8 20.3.5.0.7 20.6.3.0.7 20.6.3.0.5 20.6.3.0.10 20.6.3.0.2 20.7.2 20.9.1EFT2 20.6.3.0.11 20.6.3.1 20.6.3.0.14 20.6.4 20.9.1 20.6.3.0.19 20.6.3.0.18 20.3.6 20.9.1.1 20.6.3.0.23 20.6.4.0.4 20.6.3.0.25 20.6.5 20.6.3.0.27 20.9.2 20.9.2.1 20.6.3.0.29 20.6.3.0.31 20.6.3.0.32 20.10.1 20.6.3.0.33 20.9.2.0.01 20.9.1_LI_Images 20.10.1_LI_Images 20.9.2_LI_Images 20.3.7 20.9.3 20.6.5.1 20.11.1 20.11.1_LI_Images 20.9.3_LI_ Images 20.6.3.1.1 20.9.3.0.2 20.6.5.1.2 20.9.3.0.3 20.4.2.3 20.6.3.2 20.6.4.1 20.6.3.0.38 20.6.3.0.39 20.3.5.1 20.3.4.3 20.9.3.1 20.3.3.2 20.6.5.2 20.3.7.1 20.10.1.1 20.6.5.2.1 20.3.4.0.25 20.6.2.2.4 20.6.1.2 20.11.1.1 20.9.3.0.5 20.3.4.0.26 20.6.5.1.3 20.6.3.0.40 20.1.3.1 20.9.2.2 20.6.5.2.3 20.6.5.1.4 20.6.5.3 20.6.3.0.41 20.9.3.0.7 20.6.5.1.5 20.9.3.0.4 20.6.4.0.19 20.6.5.1.6 20.9.3.0.8 20.6.3.3 20.3.7.2 20.6.5.4 20.6.5.1.7 20.9.3.0.12 20.6.4.2 20.6.5.5 20.9.3.2 20.11.1.2 20.6.3.4 20.10.1.2 20.6.5.1.9 20.9.3.0.16 20.6.3.0.45 20.6.5.1.10 20.9.3.0.17 20.6.5.2.4 20.6.4.0.21 20.9.3.0.18 20.6.3.0.46 20.6.3.0.47 20.9.2.3 20.9.3.2_LI_Images 20.9.3.0.21 20.9.3.0.20 20.9.4_LI_Images 20.9.4 20.6.5.1.11 20.12.1 20.12.1_LI_Images 20.6.5.1.13 20.9.3.0.23 20.6.5.2.8 20.9.4.1 20.9.4.1_LI_Images 20.9.3.0.25 20.9.3.0.24 20.6.5.1.14 20.3.8 20.6.6 20.9.3.0.26 20.6.3.0.51 20.9.3.0.29 20.12.2 20.12.2_LI_Images 20.6.6.0.1 20.13.1_LI_Images 20.9.4.0.4 20.13.1 20.9.4.1.1 20.9.5 20.9.5_LI_Images 20.12.3_LI_Images 20.12.3 20.9.4.1.3 20.6.7 20.9.5.1 20.9.5.1_LI_Images 20.9.4.1.6 20.14.1 20.14.1_LI_Images 20.9.5.2 20.9.5.2.1 20.9.5.2_LI_Images 20.12.3.1 20.12.4 20.15.1_LI_Images 20.15.1 20.9.5.1.4 20.9.5.2.7 20.9.5.2.13 20.9.6 20.9.6_LI_Images 20.9.5.2.14 20.6.8 20.12.4.0.03 20.16.1 20.16.1_LI_Images 20.12.4_LI_Images 20.9.5.2.16 20.12.4.0.4 20.12.401 20.9.5.3 20.9.5.3_LI_Images 20.12.4.1_LI_Images 20.12.4.1 20.9.5.2.21 20.9.6.0.3 20.12.4.0.6 20.15.2_LI_Images 20.15.2 20.12.4_Monthly_ES5 20.12.5 20.12.5_LI_Images 20.9.7_LI _Images 20.9.7 20.15.3 20.15.3_ LI _Images 20.12.501 20.12.5.1_LI_Images 20.12.5.1 20.12.5.2_LI_Images 20.12.5.2 20.15.3.1 20.15.4_LI_Images 20.15.4 20.9.7.1_LI _Images 20.9.7.1 20.18.1 20.18.1_LI_Images 20.12.6_LI_Images 20.12.6 20.12.5.1.01 20.9.8 20.9.8_LI_Images 20.18.2 20.15.4.1_LI_Images 20.15.4.1 20.18.2_LI_Images |
References
1 LinksRecord Details
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