CVE-2026-20127

CVE-2026-20127 is a critical-severity vulnerability in Cisco Catalyst Sd-wan Manager with a CVSS 3.x base score of 10.0. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-02-25). The underlying weakness is classified as CWE-287.

Key facts

Description

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. 

Frequently asked questions

What is CVE-2026-20127?
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. 
How severe is CVE-2026-20127?
CVE-2026-20127 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-20127 being actively exploited?
Yes. CVE-2026-20127 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-02-25, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-20127?
CVE-2026-20127 primarily affects Cisco Catalyst Sd-wan Manager. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20127?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2026-20127 have an EU (EUVD) identifier?
Yes. CVE-2026-20127 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8675. It is also flagged as exploited in the EUVD (since 2026-02-25).
When was CVE-2026-20127 published?
CVE-2026-20127 was published on 2026-02-25 and last updated on 2026-06-17.

References

Affected products (6)

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