CVEs / CVE-2026-20182
CVE-2026-20182: Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability
- Known exploited in the CISA KEV catalog since 14 May 2026
- critical 10 CVSS 3.1 (from the CNA)
- EPSS 91.8% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Cisco Catalyst SD-WAN Controller & Manager contain an authentication bypass vulnerability that allows an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Cisco Catalyst SD-WAN Controller | 20.6.4 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.9.2 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.3.6 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.7.2 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.7.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.5.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.6.2 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.3.0 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.6.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 17.2.4 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.2.0 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.4.6 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.1.0 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.2.4 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.2.929 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.3.8 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.4.303 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.3.7 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.4.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.2.097 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.2.0 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.2.099 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.3.6 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.4.2 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 19.0.0 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.9.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.3.5 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.3.1 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 18.3.5 | — |
| Cisco Cisco Catalyst SD-WAN Controller | 20.6.3 | — |
Exploitation
| In CISA KEV since | 14 May 2026 |
|---|---|
| Due date for US federal agencies | 17 May 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 10 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-287 |
References
- CVE-2026-20182 on NVD
- CVE-2026-20182 in the CISA KEV catalog
- https://www.cisa.gov/news-events/directives/ed-26-03-mitigate-vulnerabilities-cisco-sd-wan-systems (cited by CISA)
- https://www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems (cited by CISA)
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa2-v69WY2SW (cited by CISA)
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk Not Applicable
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa2-v69WY2SW Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20182 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.