Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability
Cisco — Cisco Catalyst SD-WAN Manager
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.
10.0
57.8%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Published
- Feb 25, 2026
- Modified
- Jun 16, 2026
- Added to KEV
- Feb 25, 2026
- Federal patch due
- Feb 27, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2026-20127, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2026-20127 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2026-20127?
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.
How severe is CVE-2026-20127?
CVE-2026-20127 has a CVSS base score of 10.0 out of 10 (CVSS 3.1).
Is CVE-2026-20127 actively exploited in the wild?
Yes. CVE-2026-20127 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Feb 25, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-20127?
57.8% - meaning FIRST.org's EPSS model estimates a 57.8% probability this vulnerability will be exploited in the wild within 30 days (99% percentile among all scored CVEs).
What type of vulnerability is CVE-2026-20127?
CVE-2026-20127 is classified under CWE-287 (Improper Authentication).
Cross-checked against
Impactr finds and proves whether CVE-2026-20127 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
Join the waitlist