What is CVE-2026-20127?

CVE-2026-20127 is a critical-severity vulnerability in Cisco Catalyst Sd-Wan Manager, classified under Improper Authentication. CVSS score: 10.0/10. Published 2026-02-25.

How severe is CVE-2026-20127?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Is CVE-2026-20127 known to be exploited?

Yes. CVE-2026-20127 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-25), indicating it is being actively exploited. 10 public proof-of-concept repositories are indexed.

Auth bypass in Cisco Catalyst Sd-Wan Manager

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. 

Vulnerability class: Broken Authentication

EPSS: 0.882 (99.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Cisco Catalyst_sd-wan_manager — versions 20.12.6
Cisco Catalyst Sd-wan Manager — versions 20.1.12, 19.2.1, 18.4.4
Cisco Sd-wan_vbond_orchestrator — versions 20.12.6
Cisco Sd-wan_vsmart_controller — versions 20.12.6

Weakness classification (CWE)

CWE-287 — Improper Authentication

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2026-02-25. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2026-02-27.

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.

Public proof-of-concept exploits

References

psirt@cisco.com (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2026-20127?: CVE-2026-20127 is a critical-severity vulnerability in Cisco Catalyst Sd-Wan Manager, classified under Improper Authentication. CVSS score: 10.0/10. Published 2026-02-25.
How severe is CVE-2026-20127?: Critical severity. CVSS v3 base score is 10.0 out of 10.
Is CVE-2026-20127 known to be exploited?: Yes. CVE-2026-20127 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-25), indicating it is being actively exploited. 10 public proof-of-concept repositories are indexed.