CVE-2026-20293Cisco UCS and UCS-Based Appliances UEFI Shell Secure Boot Bypass Vulnerability
Updated under an hour ago ()
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It affects Cisco Enterprise NFV Infrastructure Software and 3 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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. This 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.
- CVSS
- 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-749
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- cisco
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Cisco Cisco Enterprise NFV Infrastructure Software cisco:enterprise_nfv_infrastructure_software (from the name) | 4.1.1; 3.9.1; 3.5.2; 3.12.2; 3.6.2; 3.9.2; 3.11.3; 3.11.1; and 57 more ranges | CNA record |
Cisco Cisco Unified Computing System (Managed) cisco:unified_computing_system_managed (from the name) | 4.0(1a); 4.1(1a); 4.1(1b); 4.0(4h); 4.1(1c); 4.0(4e); 4.0(4g); 4.0(2e); and 93 more ranges | CNA record |
Cisco Cisco Unified Computing System (Standalone) cisco:unified_computing_system_standalone (from the name) | 4.0(2g); 3.1(2i); 3.1(1d); 4.0(4i); 4.1(1c); 4.0(2c); 4.0(1e); 4.0(2h); and 172 more ranges | CNA record |
Cisco Cisco Unified Computing System E-Series Software (UCSE) cisco:unified_computing_system_e_series_software_ucse (from the name) | 4.11.1; 4.12.1; 4.12.2; 4.15.2; 4.15.3; 4.15.4 | CNA record |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucs-uefi-sb-bypass-eb6xC5GW
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.