Cisco Catalyst SD-WAN Controller 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.
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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk Security Impact Rating: Critical CVE: CVE-2026-20127
CSIRTS triage
- What
- A vulnerability allows unauthenticated remote attackers to bypass authentication.
- Who is affected
- Deployments of Cisco Catalyst SD-WAN Controller.
- Urgency
- Remediation is urgent due to the critical nature of the vulnerability and active exploitation.
- Action
- Apply the latest security patches from Cisco.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
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
- criticalexploited2026-002: Multiple Vulnerabilities in Cisco Productscert-eu
- unknownexploited[Update] Vulnerability in Cisco Catalyst SD-WAN (February 25, 2026)cert-fr-alerte
- criticalexploitedCVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerabilitycisa-kev
Recent advisories for Cisco Catalyst SD-WAN
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- mediumCisco Catalyst SD-WAN Manager Information Disclosure Vulnerabilitycisco-psirt · 2026-08-07
- high[NEW] [high] Cisco Catalyst SD-WAN Manager: Multiple Vulnerabilitiescert-bund · 2026-08-06
- unknownNCSC-2026-0277 [1.00] [M/H] Vulnerabilities patched in Cisco Catalyst SD-WANncsc-nl · 2026-08-06
- highCVE-2026-20313: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Cat…nvd · 2026-08-05
- highCVE-2026-20312: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Cat…nvd · 2026-08-05
- criticalCVE-2026-20310: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Cat…nvd · 2026-08-05
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