--- id: "CVE-2026-20127" kind: "vulnerability" aliases: ["CVE-2026-20127"] title: "A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco\u2026" severity: "critical" cvss: 10.0 epss: null exploited: true status: "open" category: "infrastructure" products: [{"name": "Cisco Catalyst SD-WAN Controller and Manager", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "cisco catalyst sd-wan manager", "fixed": ["20.9.8.2"], "affected": "< 20.9.8.2", "ecosystem": "vendor"}, {"name": "cisco catalyst sd-wan manager", "fixed": ["20.12.5.3"], "affected": ">= 20.11, < 20.12.5.3", "ecosystem": "vendor"}, {"name": "cisco catalyst sd-wan manager", "fixed": ["20.15.4.2"], "affected": ">= 20.13, < 20.15.4.2", "ecosystem": "vendor"}, {"name": "cisco catalyst sd-wan manager", "fixed": ["20.18.2.1"], "affected": ">= 20.16, < 20.18.2.1", "ecosystem": "vendor"}, {"name": "cisco catalyst sd-wan manager", "fixed": [], "affected": "= 20.12.6", "ecosystem": "vendor"}, {"name": "cisco sd-wan vbond orchestrator", "fixed": ["20.9.8.2"], "affected": "< 20.9.8.2", "ecosystem": "vendor"}, {"name": "cisco sd-wan vbond orchestrator", "fixed": ["20.12.5.3"], "affected": ">= 20.11, < 20.12.5.3", "ecosystem": "vendor"}, {"name": "cisco sd-wan vbond orchestrator", "fixed": ["20.15.4.2"], "affected": ">= 20.13, < 20.15.4.2", "ecosystem": "vendor"}, {"name": "cisco sd-wan vbond orchestrator", "fixed": ["20.18.2.1"], "affected": ">= 20.16, < 20.18.2.1", "ecosystem": "vendor"}, {"name": "cisco sd-wan vbond orchestrator", "fixed": [], "affected": "= 20.12.6", "ecosystem": "vendor"}, {"name": "cisco sd-wan vsmart controller", "fixed": ["20.9.8.2"], "affected": "< 20.9.8.2", "ecosystem": "vendor"}, {"name": "cisco sd-wan vsmart controller", "fixed": ["20.12.5.3"], "affected": ">= 20.11, < 20.12.5.3", "ecosystem": "vendor"}, {"name": "cisco sd-wan vsmart controller", "fixed": ["20.15.4.2"], "affected": ">= 20.13, < 20.15.4.2", "ecosystem": "vendor"}, {"name": "cisco sd-wan vsmart controller", "fixed": ["20.18.2.1"], "affected": ">= 20.16, < 20.18.2.1", "ecosystem": "vendor"}, {"name": "cisco sd-wan vsmart controller", "fixed": [], "affected": "= 20.12.6", "ecosystem": "vendor"}] ecosystems: ["vendor"] tags: ["cisco", "exploited", "infrastructure", "network-appliance", "sd-wan", "self-hosted"] not_affected_if: [] published_at: "2026-02-25T00:00:00+00:00" first_seen_at: "2026-10-23T19:11:51+00:00" updated_at: "2026-10-23T23:44:51+00:00" sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20127", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20127", "first_seen_at": "2026-10-23T23:44:51+00:00"}] --- # A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco… Cisco Catalyst SD-WAN Controller and Manager have an authentication bypass in their peering authentication mechanism. A remote attacker with no credentials can gain administrative access and manipulate SD-WAN fabric network configuration through NETCONF. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - vendor:Cisco Catalyst SD-WAN Controller and Manager affected ? fixed ? - vendor:cisco catalyst sd-wan manager affected < 20.9.8.2 fixed 20.9.8.2 - vendor:cisco catalyst sd-wan manager affected >= 20.11, < 20.12.5.3 fixed 20.12.5.3 - vendor:cisco catalyst sd-wan manager affected >= 20.13, < 20.15.4.2 fixed 20.15.4.2 - vendor:cisco catalyst sd-wan manager affected >= 20.16, < 20.18.2.1 fixed 20.18.2.1 - vendor:cisco catalyst sd-wan manager affected = 20.12.6 fixed ? - vendor:cisco sd-wan vbond orchestrator affected < 20.9.8.2 fixed 20.9.8.2 - vendor:cisco sd-wan vbond orchestrator affected >= 20.11, < 20.12.5.3 fixed 20.12.5.3 - vendor:cisco sd-wan vbond orchestrator affected >= 20.13, < 20.15.4.2 fixed 20.15.4.2 - vendor:cisco sd-wan vbond orchestrator affected >= 20.16, < 20.18.2.1 fixed 20.18.2.1 - vendor:cisco sd-wan vbond orchestrator affected = 20.12.6 fixed ? - vendor:cisco sd-wan vsmart controller affected < 20.9.8.2 fixed 20.9.8.2 - vendor:cisco sd-wan vsmart controller affected >= 20.11, < 20.12.5.3 fixed 20.12.5.3 - vendor:cisco sd-wan vsmart controller affected >= 20.13, < 20.15.4.2 fixed 20.15.4.2 - vendor:cisco sd-wan vsmart controller affected >= 20.16, < 20.18.2.1 fixed 20.18.2.1 - vendor:cisco sd-wan vsmart controller affected = 20.12.6 fixed ? ## How to check Check the Cisco advisory and CISA Emergency Directive 26-03 and Hunt & Hardening Guidance for Cisco SD-WAN Devices, which the KEV entry references; the sources do not give specific commands or settings. ## Fix Apply the fixed release named in the Cisco advisory and follow CISA guidance to hunt for compromise and harden devices; the sources do not name a fixed version. ## Timeline - 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20127 - 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-20127 ## From the sources 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. CISA required action: 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. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_