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CVE-2026-20127KEV

Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

Severity
Critical10CVSS 3.1, Critical
EPSS
88%
Published
25 Feb 2026
Updated
17 Jun 2026

Description

Title, description and vendor guidance are quoted from the source records.

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. 

Weakness: CWE-287

Known exploited

Added to CISA KEV on 25 Feb 2026

Federal remediation due date: 27 Feb 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.

Exploit prediction

88% probability of exploitation in the next 30 days (percentile 100%).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

Patcharo shows this vulnerability for information but does not match versions for this product yet.

  • 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 and 323 more

References

Provenance

Every fact on this page comes from the sources below. Nothing is written by an AI.

Cisco (CVE record)
Cisco (CVE record) · 27 Sept 2026, 23:46 UTC · Parser patcharo-cve5/1.1.0
CISA Known Exploited Vulnerabilities
CISA Known Exploited Vulnerabilities · 27 Sept 2026, 23:42 UTC · Parser patcharo-kev/1.0.0
NVD
NVD · 27 Sept 2026, 23:44 UTC · Parser patcharo-nvd/1.0.0
FIRST EPSS
FIRST EPSS · 27 Sept 2026, 23:46 UTC · Parser patcharo-epss/1.0.0

Last verified: 28 Sept 2026, 02:31 UTC