CyberSecBulletin
CVE-2026-20182Exploited in the wildNVD status: Analyzed

Cisco Catalyst SD-WAN Controller Authentication Bypass

Published Updated By the CyberSecBulletin desk

CVE-2026-20182 is a critical-severity improper authentication vulnerability in Cisco Catalyst SD-WAN Controller from Cisco, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Catalyst SD-WAN Controller versions: 20.6.4; 20.9.2; 20.3.6, and others listed below. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on May 14, 2026, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Catalyst Sd-wan Manager to 20.9.9.1 or 20.12.5.4 or 20.12.6.2 or 20.15.4.4, whichever matches your release line, or a later version.
  2. Update Sd-wan Vbond Orchestrator to 20.9.9.1 or 20.12.5.4 or 20.12.6.2 or 20.15.4.4, whichever matches your release line, or a later version.
  3. Update Sd-wan Vsmart Controller to 20.9.9.1 or 20.12.5.4 or 20.12.6.2 or 20.15.4.4, whichever matches your release line, or a later version.
  4. CISA's 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.
  5. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Catalyst SD-WAN Controller20.6.4; 20.9.2; 20.3.6; 20.7.2; 20.7.1; 20.5.1; 20.6.2; 19.3.0; and 32 more rangesNot stated
CiscoCisco Catalyst SD-WAN Manager20.1.12; 19.2.1; 18.4.4; 18.4.5; 20.1.1.1; 20.1.1; 19.2.099; 18.3.6; and 26 more rangesNot stated
CiscoCatalyst Sd-wan Managerbefore 20.9.9.1; 20.10 up to, but not including, 20.12.5.4; 20.12.6 up to, but not including, 20.12.6.2; 20.13 up to, but not including, 20.15.4.4; 20.15.5 up to, but not including, 20.15.5.2; 20.16 up to, but not including, 20.18.2.2; 26.1 up to, but not including, 26.1.1.1; 20.12.720.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2
CiscoSd-wan Vbond Orchestratorbefore 20.9.9.1; 20.10 up to, but not including, 20.12.5.4; 20.12.6 up to, but not including, 20.12.6.2; 20.13 up to, but not including, 20.15.4.4; 20.15.5 up to, but not including, 20.15.5.2; 20.16 up to, but not including, 20.18.2.2; 26.1 up to, but not including, 26.1.1.1; 20.12.720.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2
CiscoSd-wan Vsmart Controllerbefore 20.9.9.1; 20.10 up to, but not including, 20.12.5.4; 20.12.6 up to, but not including, 20.12.6.2; 20.13 up to, but not including, 20.15.4.4; 20.15.5 up to, but not including, 20.15.5.2; 20.16 up to, but not including, 20.18.2.2; 26.1 up to, but not including, 26.1.1.1; 20.12.720.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (cisco.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  3. Added to CISA's Known Exploited Vulnerabilities catalogue.
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Cisco Catalyst SD-WAN Controller

All Cisco Catalyst SD-WAN Controller vulnerabilities

Recent Improper Authentication vulnerabilities

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