Background exploitation KEV catalog No authentication
CVE-2026-20127

Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

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…

CheckOps priority index
9.1/10 Patch within 24 h
Severity10.0
Probability8.9
Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 89.3% higher than 99.8% of CVEs
CVSS 3.1 10.0 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:
Exploited for 251 days 25 Feb 2026
CISA due date 27 Feb 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

  • KEV catalog (CISA)25 Feb 2026
  • Exploited in EUVD (ENISA)25 Feb 2026
  • Used by ransomwareno
  • EPSS above 10 %89.3%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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. 

Affected products

Cisco Catalyst SD-WAN ManagerCatalyst SD-WAN Controller and Manager
Affected versions
  • 18.3.7
  • 20.9.4.1.1
  • 20.3.7.1
  • 20.6.4.1
  • 18.4.6
  • 20.1.2_937
  • 19.2.4.0.1
  • 20.3.4.0.11
  • 20.9.4.1.3
  • 20.12.5.1
  • 20.3.3.0.17
  • 20.3.2.1_927
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 89.3%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-76418Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
    5.3 · Rising fast
  • CVE-2026-76519Cisco Secure Email Gateway Relative Path Traversal Vulnerability
    5.8 · Rising fast
  • CVE-2026-76504Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
    7.5 · Actively exploited
  • CVE-2026-76460Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
    8.7 · Actively exploited
  • CVE-2026-76461Cisco Secure Email Gateway SQL Injection Vulnerability
    7.2 · Actively exploited
  • CVE-2026-20079Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
    9.1 · Actively exploited

Are you affected?

CheckOps reads your SBOMs and scans, and alerts you as soon as one of your dependencies is exploited.

Get notified at launch

Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities