CVE-2026-20293

CVE Enrichment

CVSS: 7.1 HIGH
EPSS: 0.16%
EPSS Percentile: 4.52%
CISA KEV: Not listed

Description

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.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: psirt@cisco.com
Published: 09-Sep-2026 00:17
Last Modified: 11-Sep-2026 21:17
EPSS Date: 2026-10-16
CWE: CWE-749

CVSS Vector


            CVSS:3.1                            AV:L /
                            AC:L /
                            PR:L /
                            UI:N /
                            S:U /
                            C:H /
                            I:H /
                            A:N

References

psirt@cisco.com

Last enrichment sync: 17-Oct-2026 11:55
Sources: NVD · FIRST EPSS · CISA KEV
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Reported Context (1)

The disclosure resulted in three vulnerabilities tracked as CVE-2026-20293 for Cisco, CVE-2026-33197 for AMI Aptio-based systems, and CVE-2026-6485 for Insyde. InfraTrust Report Finds Exploited Flaws in Infrastructure Management Systems

CVE (11)

Malware (2)

People (1)

Threat Actors (4)

MITRE ATT&CK (4)

Vendors (7)

Products (10)

Tools (1)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.