← Vulnerability feed

Vulnerability record · CVE-2026-20293 · published 8 September 2026

CVE-2026-20293: A vulnerability in the Unified Extensible Firmware Interface (UEFI) Shell implementation of Cisco UCS Servers …

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.

7.1 CVSS 3.1 High EPSS 0.16% · top 95.7% CWE-749 · CWE-749 Awaiting Analysis
7.1CVSS 3.1 base score
0.16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
1References
11 Sep 2026Last modified by NVD

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.

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

References

LinkTags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucs-uefi-sb-bypass-eb6xC5GW

Track CVE-2026-20293 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.8CVE-2018-19322GIGABYTE driver IO port access allows privilege escalationThe GPCIDrv and GDrv low-level drivers shipped with GIGABYTE APP Center, AORUS GRAPHICS ENGINE, XTREME GAMING ENGINE and OC GURU II expose IO port re…KEVEPSS 1.8%analysed7.5CVE-2010-1428JBoss EAP Web Console access control bypass via non-GET/POST methodsThe Web Console in JBoss Enterprise Application Platform enforces access control only for GET and POST requests, so any other HTTP method bypasses th…KEVEPSS 62%analysed5.3CVE-2010-0738JBoss JMX-Console access control bypass via non-GET/POST HTTP methodsThe JMX-Console web application in Red Hat JBoss EAP 4.2 before 4.2.0.CP09 and 4.3 before 4.3.0.CP08 enforces access control only for GET and POST re…KEVEPSS 79%analysed7.5CVE-2006-1547Apache Struts 1 ActionForm multipart parameter denial of serviceApache Struts before 1.2.9 with BeanUtils 1.7 exposes the public getMultipartRequestHandler method through ActionForm parameter binding. A remote att…KEVEPSS 55%analysed

Source: NIST National Vulnerability Database (record CVE-2026-20293), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.