CVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, contain an authentication bypass vulnerability 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.
CSIRTS triage
- What
- An authentication bypass vulnerability allows unauthenticated remote attackers to gain administrative privileges.
- Who is affected
- Unauthenticated remote attackers targeting Cisco Catalyst SD-WAN Controller and Manager.
- Urgency
- Remediation is urgent due to active exploitation and critical severity.
- Action
- Apply the latest security updates from Cisco.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-20127
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-20127Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.8% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-20127 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownexploitedCisco Catalyst SD-WAN Controller, Catalyst SD-WAN Manager, and Catalyst SD-WAN Validator Authenticated Privile…cisco-psirt
- criticalexploitedCisco Catalyst SD-WAN Controller Authentication Bypass Vulnerabilitycisco-psirt
- criticalexploited2026-002: Multiple Vulnerabilities in Cisco Productscert-eu
- unknownexploited[Update] Vulnerability in Cisco Catalyst SD-WAN (February 25, 2026)cert-fr-alerte
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