{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-20293","assignerOrgId":"d1c1063e-7a18-46af-9102-31f8928bc633","state":"PUBLISHED","assignerShortName":"cisco","dateReserved":"2025-10-08T11:59:15.405Z","datePublished":"2026-09-08T16:04:40.874Z","dateUpdated":"2026-09-16T03:57:05.926Z"},"containers":{"cna":{"title":"Cisco UCS and UCS-Based Appliances UEFI Shell Secure Boot Bypass Vulnerability","metrics":[{"format":"cvssV3_1","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"}}],"descriptions":[{"lang":"en","value":"A vulnerability in the Unified Extensible Firmware Interface (UEFI) Shell implementation of Cisco UCS Servers and UCS-based appliances could allow an authenticated attacker with valid credentials for a user account with the role of user or admin or an unauthenticated attacker with physical access to an affected device to bypass UEFI Secure Boot validation checks and execute unauthorized software.\r\n\r\nThis vulnerability is due to the availability of memory write commands in the UEFI Shell while UEFI Secure Boot is enabled on a device. An attacker could exploit this vulnerability by selecting the UEFI Shell boot option at boot time and using available shell commands to modify UEFI memory variables. A successful exploit could allow the attacker to manipulate the preboot environment, overwrite UEFI Secure Boot-related memory values, and execute unauthorized software on the affected device."}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucs-uefi-sb-bypass-eb6xC5GW","name":"cisco-sa-ucs-uefi-sb-bypass-eb6xC5GW"}],"exploits":[{"lang":"en","value":"The Cisco PSIRT is aware that proof-of-concept exploit code is available for the vulnerability described in this advisory.\r\n\r\nThe Cisco PSIRT is not aware of any malicious use of the vulnerability that is described in this advisory."}],"source":{"advisory":"cisco-sa-ucs-uefi-sb-bypass-eb6xC5GW","discovery":"EXTERNAL","defects":["CSCwt77804"]},"problemTypes":[{"descriptions":[{"lang":"en","description":"Exposed Dangerous Method or Function","type":"cwe","cweId":"CWE-749"}]}],"affected":[{"vendor":"Cisco","product":"Cisco Enterprise NFV Infrastructure 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Unified Computing System 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