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CVE-2026-20127

Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

Published: Feb 25, 2026Updated: Jun 17, 2026 Sources: CVE List NVD BDUCWE-287
10.0CRITICAL
NVD MITRE
EPSS Score
88.2%
Top 0.2%
CISA KEV
Active Exploitation
Since Feb 25, 2026
Exploits
0 Known
Remediation
Patch Available
Self-Check
OpenVAS

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. 

In plain language

AI Act now

CVE-2026-20127 lets an attacker bypass login to Cisco Catalyst SD-WAN controllers and make high-privilege changes to your network; if you run these products, you should treat this as an immediate, serious risk.

Executive summary

CVE-2026-20127 is an authentication-bypass flaw (CWE-287) in Cisco Catalyst SD-WAN peering authentication, where an unauthenticated remote attacker can send crafted requests to bypass authentication, obtain an administrative session, and then use NETCONF to manipulate SD-WAN network configuration; it is confirmed in CISA KEV and has been reported exploited in real attacks.

If affected, business impact
Full SD-WAN configuration takeoverService disruption and outage riskUnauthorized network traffic changesLoss of administrative control

What to do now

  1. Check whether you use Cisco catalyst sd-wan manager, sd-wan vbond orchestrator, sd-wan vsmart controller, cisco catalyst sd-wan controller, or cisco catalyst sd-wan manager, and whether they could be reachable from the network (directly or via SD-WAN peering paths).
  2. Confirm your current running software version(s) on each affected device.
  3. Upgrade all affected SD-WAN components to the fixed release: 20.9.8.2.
  4. If you cannot upgrade immediately, restrict network access so the devices are not reachable from untrusted networks and follow Cisco/CISA hardening guidance until upgrades are completed.
  5. After upgrading, monitor for signs of unauthorized configuration changes and validate that SD-WAN controller/peering status and configuration match your expected state.
Patch / advisory Usually a quick update

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-287

Affected Products

Cisco Systems Inc.
commercial·USaka cisco, cisco systems
Catalyst SD-WAN Manager
Networking Infrastructure
sd-wan vbond orchestrator
Networking Infrastructure
sd-wan vsmart controller
Networking Infrastructure
Cisco Catalyst SD-WAN Controller
Networking Infrastructure
Cisco Catalyst SD-WAN Manager
Networking Infrastructure
and 1 more affected products View all →

Exploitability

CISA Known Exploited Vulnerability
Added to KEV:Feb 25, 2026
Remediation due:Feb 27, 2026

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.

0 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available
Is your org exposed to CVE-2026-20127?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk
sec.cloudapps.cisco.com
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20127
cisa.gov
News mentions
13
See all →

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