{"id":"CVE-2026-20127","published":"2026-02-25T17:25:29Z","modified":"2026-06-17T15:06:12Z","title":"Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability","vendor":"Cisco","product":"Catalyst SD-WAN Controller and Manager","tier":"core","eol":null,"description":{"text":"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.\r\n\r\nThis 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. ","provenance":"source","from":"NVD"},"summary":{"text":"The authentication bypass is in the peering authentication mechanism of Cisco Catalyst SD-WAN Controller (formerly vSmart), Cisco Catalyst SD-WAN Manager (formerly vManage), and Cisco Catalyst SD-WAN Validator (formerly vBond). An unauthenticated remote attacker who sends crafted requests to an affected system can log in as an internal, high-privileged, non-root user on a Controller, then use NETCONF to manipulate the SD-WAN fabric's network configuration.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:11:41Z"},"cvss":{"score":10.0,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.89294,"percentile":0.99782,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-02-25","dueDate":"2026-02-27","ransomware":false,"requiredAction":"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.","notes":"CISA Mitigation Instructions: https://www.cisa.gov/news-events/directives/ed-26-03-mitigate-vulnerabilities-cisco-sd-wan-systems ; https://www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk ; https://nvd.nist.gov/vuln/detail/CVE-2026-20127","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-02-25","exploitedFirstSeen":"2026-02-25","ransomware":false,"evidence":[{"url":"https://blog.talosintelligence.com/uat-8616-sd-wan/","date":"2026-02-25"},{"url":"https://media.defense.gov/2026/Feb/25/2003880301/-1/-1/0/CSA_Exploitation_of_SD-WAN_Appliances.PDF","date":"2026-02-25"},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk","date":"2026-02-25"},{"url":"https://www.cisa.gov/news-events/directives/ed-26-03-mitigate-vulnerabilities-cisco-sd-wan-systems","date":"2026-02-25"},{"url":"https://www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems","date":"2026-02-25"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-02-25"},{"url":"https://x.com/ethicalhack3r/status/2029244376908435492","date":"2026-03-04"},{"url":"https://x.com/SimoKohonen/status/2029483790909702425","date":"2026-03-05"},{"url":"https://tracker.crowdsec.net/cves/CVE-2026-20127","date":"2026-03-06"},{"url":"https://asec.ahnlab.com/en/92906/","date":"2026-03-12"}],"evidenceTotal":20,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"[ShadowBrieferFeed] Hackers Exploited Cisco SD-WAN Flaw to Plant Malware Built to Steal Encryption K","url":"https://otx.alienvault.com/pulse/6ae41f8c14f134b310e31bcc","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Volt Typhoon Used Covert Silent Train Network in Four Zero-Day Exploitation Campaigns","url":"https://otx.alienvault.com/pulse/6ae25986a5a09777ff89d848","created":"2026-10-28"},{"name":"Volt Typhoon Used Covert Silent Train Network in Four Zero-Day Exploitation Campaigns","url":"https://otx.alienvault.com/pulse/6ae259725b3c2c4fc06aa20e","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"}],"provenance":"machine"},"cwes":[{"id":"CWE-287","name":"Improper Authentication"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20127","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: unauthenticated remote exploit of public-facing management interface","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"could allow an unauthenticated, remote attacker to bypass authentication","start":223,"end":295}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: attacker logs in with internal privileged account","mappingType":"primary_impact","evidence":[{"from":"description","quote":"log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged","start":622,"end":708}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1098","name":"Account Manipulation","tactics":["persistence","privilege-escalation"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: gains administrative privileges via authentication bypass","mappingType":"primary_impact","evidence":[{"from":"description","quote":"obtain administrative privileges on an affected system","start":300,"end":354}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-8675","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-8675","exploited":true,"exploitedSince":"2026-02-25","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":8,"skipped":1,"earliest":"2026-03-04","earliestUrl":"https://github.com/zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE","repos":[{"name":"zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE","url":"https://github.com/zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE","stars":30,"created":"2026-03-04"},{"name":"sfewer-r7/CVE-2026-20127","url":"https://github.com/sfewer-r7/CVE-2026-20127","stars":24,"created":"2026-03-09"},{"name":"BugFor-Pings/CVE-2026-20127_EXP","url":"https://github.com/BugFor-Pings/CVE-2026-20127_EXP","stars":4,"created":"2026-03-05"},{"name":"yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE","url":"https://github.com/yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE","stars":2,"created":"2026-03-07"},{"name":"gigachadusers/cve-2026-20127","url":"https://github.com/gigachadusers/cve-2026-20127","stars":2,"created":"2026-04-15"}]},"metasploit":[{"name":"Cisco Catalyst SD-WAN Controller Authentication Bypass","module":"auxiliary/admin/networking/cisco_sdwan_auth_bypass","type":"auxiliary","disclosureDate":"2026-02-25","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/admin/networking/cisco_sdwan_auth_bypass.rb"}],"first":{"date":"2026-02-25","source":"Metasploit","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/admin/networking/cisco_sdwan_auth_bypass.rb"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1078","T1098"],"provenance":"ai"}],"timeline":[{"date":"2026-02-25","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20127","provenance":"source"},{"date":"2026-02-25","kind":"exploit-public","label":"First public exploit: Metasploit; later: PoC-in-GitHub 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use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.96,"detail":"percentile 0.9978"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"8 PoC-in-GitHub repos; 1 Metasploit module"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":7.0,"detail":"base score 10.0"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}