Vulnerability record · CVE-2026-20182 · published 14 May 2026
CVE-2026-20182: Cisco Catalyst SD-WAN peering authentication bypass grants admin access
Cisco · Catalyst Sd Wan Manager
The peering authentication mechanism in Cisco Catalyst SD-WAN Controller, Manager and Validator does not work properly, allowing crafted requests to bypass authentication. An unauthenticated remote attacker can obtain an internal high-privileged non-root account and reach NETCONF to manipulate SD-WAN fabric configuration.
Description
May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and fixed after the was disclosed in February 2026. This new advisory is for a new vulnerability in the control connection handshaking. The section of this advisory includes Show Control Connections guidance to help with system checks. 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 the 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Automated analysis
critical priorityCVSS 10.0 unauthenticated remote authentication bypass with scope change, KEV listing and near-certain EPSS probability make this an urgent patch-first issue.
What it is
The peering authentication mechanism in Cisco Catalyst SD-WAN Controller, Manager and Validator does not work properly, allowing crafted requests to bypass authentication. An unauthenticated remote attacker can obtain an internal high-privileged non-root account and reach NETCONF to manipulate SD-WAN fabric configuration.
Impact
An attacker gains administrative, non-root access to the SD-WAN Controller and can use NETCONF to alter network configuration across the SD-WAN fabric.
Attack surface
Reachable over the network via crafted requests to the control connection handshaking/peering authentication path; no authentication or user interaction is required per the CVSS vector (AV:N/AC:L/PR:N/UI:N).
Exploitation
Listed in CISA KEV on 2026-05-14 with a 2026-05-17 remediation due date, and EPSS 30-day probability is 0.91522 (99.8th percentile), indicating active exploitation is expected or observed. No ransomware campaign use is documented.
What to do
- Apply the fixed software from the Cisco advisory cisco-sa-sdwan-rpa2-v69WY2SW immediately, prioritizing internet-exposed Controller, Manager and Validator instances.
- Follow CISA Emergency Directive 26-03 and the CISA Hunt & Hardening Guidance for Cisco SD-WAN Devices.
- Restrict management and peering interfaces from untrusted networks and review Show Control Connections output for unexpected peers.
- Rotate credentials and review accounts on affected systems for unauthorized high-privileged non-root accounts.
- If mitigations are not available, discontinue use of the product per BOD 22-01 guidance for cloud services.
Detection
- Audit SD-WAN Controller, Manager and Validator logs for unexpected or malformed peering/control connection handshake attempts.
- Review Show Control Connections output for unauthorized or anomalous peer entries.
- Monitor NETCONF sessions and configuration changes originating from unexpected accounts or sources.
- Alert on creation or use of internal high-privileged non-root accounts on SD-WAN management components.
This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.
Exploitation in the wild
CISA added CVE-2026-20182 to the Known Exploited Vulnerabilities catalog on 14 May 2026 as "Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability". Required action: Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlined 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. Federal deadline 17 May 2026.
Affected products
3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
Track CVE-2026-20182 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-20182), CISA KEV, FIRST EPSS (scores of 2026-09-24). This page is refreshed as NVD updates the record.
