Strix
63.8K

CVE-2026-20293

HIGHCVSS 7.1/10EPSS 0.13%

Last modified

CVE-2026-20293 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. 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. EPSS estimates a 0.13% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.1/10

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

EPSS Probability
0.13%

3.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
CiscoCisco Enterprise NFV Infrastructure Software4.1.1; 3.9.1; 3.5.2; 3.12.2; 3.6.2; 3.9.2; 3.11.3; 3.11.1; 3.5.1; 3.3.1; 3.10.2; 3.12.1b; 3.4.1; 3.12.1a; 3.6.3; 3.8.1; 3.11.2; 3.12.1; 3.12.3; 3.10.1; 3.6.1; 3.10.3; 3.7.1; 4.1.2; 4.2.1; 4.2.2; 4.4.1; 4.4.2; 4.5.1; 4.4.3; 4.6.1; 4.7.1; 4.6.2-FC2; 4.6.2; 4.8.1; 4.8.2; 4.9.1; 4.6.3; 4.9.2; 4.10.1; 4.9.3; 4.11.1; 4.9.4; 4.12.1; 4.6.4; 4.12.2; 4.13.1; 4.9.5; 4.12.3; 4.14.1; 4.6.3-FC4; 4.9.4-FC3; 4.12.4; 4.15.1; 4.9.6; 4.15.2; 4.12.5; 4.15.3; 4.15.4; 4.12.6; 4.15.5; 4.12.7; 4.12.8; 4.15.6; 4.9.10
CiscoCisco Unified Computing System (Managed)4.0(1a); 4.1(1a); 4.1(1b); 4.0(4h); 4.1(1c); 4.0(4e); 4.0(4g); 4.0(2e); 4.0(4a); 4.0(2d); 4.0(1b); 4.0(4f); 4.0(4c); 4.0(1c); 4.0(4b); 4.0(2b); 4.0(4d); 4.0(2a); 4.0(1d); 4.0(4i); 4.1(1d); 4.1(2a); 4.1(1e); 4.1(2b); 4.0(4k); 4.1(3a); 4.1(3b); 4.1(2c); 4.0(4l); 4.1(4a); 4.1(3c); 4.1(3d); 4.2(1c); 4.2(1d); 4.0(4m); 4.1(3e); 4.2(1f); 4.1(3f); 4.2(1i); 4.2(1k); 4.0(4n); 4.1(3h); 4.2(1l); 4.2(1m); 4.1(3i); 4.2(2a); 4.2(1n); 4.1(3j); 4.2(2c); 4.2(2d); 4.2(3b); 4.1(3k); 4.0(4o); 4.2(2e); 4.2(3d); 4.2(3e); 4.2(3g); 4.1(3l); 4.3(2b); 4.2(3h); 4.2(3i); 4.3(2c); 4.1(3m); 4.3(2e); 4.3(3a); 4.2(3j); 4.3(3c); 4.3(4a); 4.2(3k); 4.3(4b); 4.3(4c); 4.2(3l); 4.3(4d); 4.2(3m); 4.3(2f); 4.3(5a); 4.3(4e); 4.1(3n); 4.3(4f); 4.2(3n); 4.3(5c); 4.2(3o); 4.3(5d); 4.3(6a); 4.3(6b); 4.3(5e); 4.3(6c); 6.0(1b); 4.2(3p); 6.0(1c); 4.3(6d); 6.0(1d); 6.0(1e); 4.3(6e); 6.0(1f); 4.3(6f); 6.0(2b); 6.0(1h); 4.2(3r); 6.0(2c); 4.3(6g)
CiscoCisco Unified Computing System (Standalone)4.0(2g); 3.1(2i); 3.1(1d); 4.0(4i); 4.1(1c); 4.0(2c); 4.0(1e); 4.0(2h); 4.0(4h); 4.0(1h); 4.0(2l); 3.1(3g); 4.0(1.240); 4.0(2f); 4.0(1g); 4.0(2i); 3.1(3i); 4.0(4d); 4.1(1d); 3.1(3c); 4.0(4k); 3.1(2d); 3.1(3a); 3.1(3j); 4.0(2d); 4.1(1f); 4.0(4j); 4.0(2m); 4.0(2k); 4.0(1c); 4.0(4f); 4.0(4c); 3.1(3d); 3.1(2g); 3.1(2c); 4.0(1d); 3.1(2e); 4.0(1a); 4.0(1b); 3.1(3b); 4.0(4b); 3.1(2b); 4.0(4e); 3.1(3h); 4.0(4l); 4.1(1g); 4.1(2a); 4.0(2n); 4.1(1h); 3.1(3k); 4.1(2b); 4.0(2o); 4.0(4m); 4.1(2d); 4.1(3b); 4.0(2p); 4.1(2e); 4.1(2f); 4.0(4n); 4.0(2q); 4.1(3c); 4.0(2r); 4.1(3d); 4.1(2g); 4.1(2h); 4.1(3g); 4.1(3f); 4.1(2j); 4.1(2k); 4.1(3h); 4.2(2a); 4.1(3i); 4.2(2f); 4.2(2g); 4.2(3b); 4.1(3l); 4.2(3d); 4.3(1.230097); 4.2(1e); 4.2(1b); 4.2(1j); 4.2(1i); 4.2(1f); 4.2(1a); 4.2(1c); 4.2(1g); 4.3(1.230124); 4.1(2l); 4.2(3e); 4.3(1.230138); 4.2(3g); 4.3(2.230207); 4.2(3h); 4.2(3i); 4.3(2.230270); 4.1(3m); 4.1(2m); 4.3(2.240002); 4.3(3.240022); 4.2(3j); 4.1(3n); 4.3(2.240009); 4.3(3.240041); 4.2(3k); 4.3(3.240043); 4.3(4.240142); 4.3(2.240037); 4.3(2.240053); 4.3(4.240152); 4.2(3l); 4.3(2.240077); 4.3(4.242028); 4.3(4.241063); 4.3(4.242038); 4.2(3m); 4.3(2.240090); 4.3(5.240021); 4.3(2.240107); 4.3(4.242066); 4.2(3n); 4.3(5.250001); 4.2(3o); 4.3(2.250016); 4.3(2.250021); 4.3(5.250030); 4.3(2.250022); 4.3(6.250039); 4.3(6.250040); 4.3(5.250033); 4.3(6.250044); 4.3(6.250053); 4.3(2.250037); 4.3(2.250045); 4.3(4.252001); 4.3(4.252002); 6.0(1.250127); 4.2(3p); 6.0(1.250131); 4.3(6.250101); 6.0(1.250174); 4.3(6.250117); 4.3(5.250043); 4.3(5.250045); 4.3(6.250060); 6.0(1.250130); 4.3(4.241014); 6.0(1.251030); 4.3(2.250063); 6.0(1.250192); 4.3(6.260003); 6.0(1.250194); 6.0(1.260001); 4.3(6.260017); 4.3(2.260007); 6.0(2.260044); 6.0(2.260042); 4.0(1.260003); 2.0(2.260062); 2.0(1.250127); 2.0(1.250096); 4.0(1.260004); 6.0(2.260026); 6.0(1.251006); 1.2(0.250011); 1.1(0.250016); 1.0(0.240001); 1.0(0.250003); 1.2(0.250013); 1.1(0.250026); 1.0(1.250002); 1.1(0.250022); 1.1(0.250025); 1.0(1.250032); 6.0(2.260034); 6.0(2.260069); 4.3(6.260033); 2.0(2.260101); 4.2(3q); 4.2(3r); 1.2(0.260005)
CiscoCisco Unified Computing System E-Series Software (UCSE)4.11.1; 4.12.1; 4.12.2; 4.15.2; 4.15.3; 4.15.4

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-20293?
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.
How severe is CVE-2026-20293?
CVE-2026-20293 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.
How do I fix CVE-2026-20293?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →

Are you affected by CVE-2026-20293?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST