CVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager (Critical, CVSS 10)
- CVSS
- 10 Critical (v3.1)
- EPSS
- 89.3% chance of exploitation in the next 30 days (higher than 99.7% of CVEs)
- Exploited in the wild
- Yes, on CISA’s KEV list since Feb 25, 2026
- Public exploit
- Yes, reported in a Metasploit module and 9 GitHub repositories
- Weakness
- CWE-287
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- Published
- Feb 25, 2026
- CISA fix-by date
- Feb 27, 2026 (for US federal agencies)
What it is
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.
Description from the National Vulnerability Database.
What to do
CISA: 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 av
Check whether you run Cisco Catalyst SD-WAN Controller and Manager, then apply the vendor’s fix or mitigation from the advisories below. Because this flaw is exploited or has public exploit code, treat it as urgent and check for signs of compromise, not just the patch level.
Advisories and fixes
ThreatRoundup coverage
Volt Typhoon’s ‘Silent Train’ Rode Four Zero-Days Into Network Control
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.