CVE-2026-20293 vulnerability in Cisco Products
Published on September 8, 2026
Cisco UCS and UCS-Based Appliances UEFI Shell Secure Boot Bypass Vulnerability
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.
Vulnerability Analysis
CVE-2026-20293 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE
Weakness Type
Exposed Dangerous Method or Function
The software provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.
Products Associated with CVE-2026-20293
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Affected Versions
Cisco Enterprise NFV Infrastructure Software:- Version 4.1.1 is affected.
- Version 3.9.1 is affected.
- Version 3.5.2 is affected.
- Version 3.12.2 is affected.
- Version 3.6.2 is affected.
- Version 3.9.2 is affected.
- Version 3.11.3 is affected.
- Version 3.11.1 is affected.
- Version 3.5.1 is affected.
- Version 3.3.1 is affected.
- Version 3.10.2 is affected.
- Version 3.12.1b is affected.
- Version 3.4.1 is affected.
- Version 3.12.1a is affected.
- Version 3.6.3 is affected.
- Version 3.8.1 is affected.
- Version 3.11.2 is affected.
- Version 3.12.1 is affected.
- Version 3.12.3 is affected.
- Version 3.10.1 is affected.
- Version 3.6.1 is affected.
- Version 3.10.3 is affected.
- Version 3.7.1 is affected.
- Version 4.1.2 is affected.
- Version 4.2.1 is affected.
- Version 4.2.2 is affected.
- Version 4.4.1 is affected.
- Version 4.4.2 is affected.
- Version 4.5.1 is affected.
- Version 4.4.3 is affected.
- Version 4.6.1 is affected.
- Version 4.7.1 is affected.
- Version 4.6.2-FC2 is affected.
- Version 4.6.2 is affected.
- Version 4.8.1 is affected.
- Version 4.8.2 is affected.
- Version 4.9.1 is affected.
- Version 4.6.3 is affected.
- Version 4.9.2 is affected.
- Version 4.10.1 is affected.
- Version 4.9.3 is affected.
- Version 4.11.1 is affected.
- Version 4.9.4 is affected.
- Version 4.12.1 is affected.
- Version 4.6.4 is affected.
- Version 4.12.2 is affected.
- Version 4.13.1 is affected.
- Version 4.9.5 is affected.
- Version 4.12.3 is affected.
- Version 4.14.1 is affected.
- Version 4.6.3-FC4 is affected.
- Version 4.9.4-FC3 is affected.
- Version 4.12.4 is affected.
- Version 4.15.1 is affected.
- Version 4.9.6 is affected.
- Version 4.15.2 is affected.
- Version 4.12.5 is affected.
- Version 4.15.3 is affected.
- Version 4.15.4 is affected.
- Version 4.12.6 is affected.
- Version 4.15.5 is affected.
- Version 4.12.7 is affected.
- Version 4.12.8 is affected.
- Version 4.15.6 is affected.
- Version 4.9.10 is affected.
- Version 4.0(1a) is affected.
- Version 4.1(1a) is affected.
- Version 4.1(1b) is affected.
- Version 4.0(4h) is affected.
- Version 4.1(1c) is affected.
- Version 4.0(4e) is affected.
- Version 4.0(4g) is affected.
- Version 4.0(2e) is affected.
- Version 4.0(4a) is affected.
- Version 4.0(2d) is affected.
- Version 4.0(1b) is affected.
- Version 4.0(4f) is affected.
- Version 4.0(4c) is affected.
- Version 4.0(1c) is affected.
- Version 4.0(4b) is affected.
- Version 4.0(2b) is affected.
- Version 4.0(4d) is affected.
- Version 4.0(2a) is affected.
- Version 4.0(1d) is affected.
- Version 4.0(4i) is affected.
- Version 4.1(1d) is affected.
- Version 4.1(2a) is affected.
- Version 4.1(1e) is affected.
- Version 4.1(2b) is affected.
- Version 4.0(4k) is affected.
- Version 4.1(3a) is affected.
- Version 4.1(3b) is affected.
- Version 4.1(2c) is affected.
- Version 4.0(4l) is affected.
- Version 4.1(4a) is affected.
- Version 4.1(3c) is affected.
- Version 4.1(3d) is affected.
- Version 4.2(1c) is affected.
- Version 4.2(1d) is affected.
- Version 4.0(4m) is affected.
- Version 4.1(3e) is affected.
- Version 4.2(1f) is affected.
- Version 4.1(3f) is affected.
- Version 4.2(1i) is affected.
- Version 4.2(1k) is affected.
- Version 4.0(4n) is affected.
- Version 4.1(3h) is affected.
- Version 4.2(1l) is affected.
- Version 4.2(1m) is affected.
- Version 4.1(3i) is affected.
- Version 4.2(2a) is affected.
- Version 4.2(1n) is affected.
- Version 4.1(3j) is affected.
- Version 4.2(2c) is affected.
- Version 4.2(2d) is affected.
- Version 4.2(3b) is affected.
- Version 4.1(3k) is affected.
- Version 4.0(4o) is affected.
- Version 4.2(2e) is affected.
- Version 4.2(3d) is affected.
- Version 4.2(3e) is affected.
- Version 4.2(3g) is affected.
- Version 4.1(3l) is affected.
- Version 4.3(2b) is affected.
- Version 4.2(3h) is affected.
- Version 4.2(3i) is affected.
- Version 4.3(2c) is affected.
- Version 4.1(3m) is affected.
- Version 4.3(2e) is affected.
- Version 4.3(3a) is affected.
- Version 4.2(3j) is affected.
- Version 4.3(3c) is affected.
- Version 4.3(4a) is affected.
- Version 4.2(3k) is affected.
- Version 4.3(4b) is affected.
- Version 4.3(4c) is affected.
- Version 4.2(3l) is affected.
- Version 4.3(4d) is affected.
- Version 4.2(3m) is affected.
- Version 4.3(2f) is affected.
- Version 4.3(5a) is affected.
- Version 4.3(4e) is affected.
- Version 4.1(3n) is affected.
- Version 4.3(4f) is affected.
- Version 4.2(3n) is affected.
- Version 4.3(5c) is affected.
- Version 4.2(3o) is affected.
- Version 4.3(5d) is affected.
- Version 4.3(6a) is affected.
- Version 4.3(6b) is affected.
- Version 4.3(5e) is affected.
- Version 4.3(6c) is affected.
- Version 6.0(1b) is affected.
- Version 4.2(3p) is affected.
- Version 6.0(1c) is affected.
- Version 4.3(6d) is affected.
- Version 6.0(1d) is affected.
- Version 6.0(1e) is affected.
- Version 4.3(6e) is affected.
- Version 6.0(1f) is affected.
- Version 4.3(6f) is affected.
- Version 6.0(2b) is affected.
- Version 6.0(1h) is affected.
- Version 4.2(3r) is affected.
- Version 6.0(2c) is affected.
- Version 4.3(6g) is affected.
- Version 4.0(2g) is affected.
- Version 3.1(2i) is affected.
- Version 3.1(1d) is affected.
- Version 4.0(4i) is affected.
- Version 4.1(1c) is affected.
- Version 4.0(2c) is affected.
- Version 4.0(1e) is affected.
- Version 4.0(2h) is affected.
- Version 4.0(4h) is affected.
- Version 4.0(1h) is affected.
- Version 4.0(2l) is affected.
- Version 3.1(3g) is affected.
- Version 4.0(1.240) is affected.
- Version 4.0(2f) is affected.
- Version 4.0(1g) is affected.
- Version 4.0(2i) is affected.
- Version 3.1(3i) is affected.
- Version 4.0(4d) is affected.
- Version 4.1(1d) is affected.
- Version 3.1(3c) is affected.
- Version 4.0(4k) is affected.
- Version 3.1(2d) is affected.
- Version 3.1(3a) is affected.
- Version 3.1(3j) is affected.
- Version 4.0(2d) is affected.
- Version 4.1(1f) is affected.
- Version 4.0(4j) is affected.
- Version 4.0(2m) is affected.
- Version 4.0(2k) is affected.
- Version 4.0(1c) is affected.
- Version 4.0(4f) is affected.
- Version 4.0(4c) is affected.
- Version 3.1(3d) is affected.
- Version 3.1(2g) is affected.
- Version 3.1(2c) is affected.
- Version 4.0(1d) is affected.
- Version 3.1(2e) is affected.
- Version 4.0(1a) is affected.
- Version 4.0(1b) is affected.
- Version 3.1(3b) is affected.
- Version 4.0(4b) is affected.
- Version 3.1(2b) is affected.
- Version 4.0(4e) is affected.
- Version 3.1(3h) is affected.
- Version 4.0(4l) is affected.
- Version 4.1(1g) is affected.
- Version 4.1(2a) is affected.
- Version 4.0(2n) is affected.
- Version 4.1(1h) is affected.
- Version 3.1(3k) is affected.
- Version 4.1(2b) is affected.
- Version 4.0(2o) is affected.
- Version 4.0(4m) is affected.
- Version 4.1(2d) is affected.
- Version 4.1(3b) is affected.
- Version 4.0(2p) is affected.
- Version 4.1(2e) is affected.
- Version 4.1(2f) is affected.
- Version 4.0(4n) is affected.
- Version 4.0(2q) is affected.
- Version 4.1(3c) is affected.
- Version 4.0(2r) is affected.
- Version 4.1(3d) is affected.
- Version 4.1(2g) is affected.
- Version 4.1(2h) is affected.
- Version 4.1(3g) is affected.
- Version 4.1(3f) is affected.
- Version 4.1(2j) is affected.
- Version 4.1(2k) is affected.
- Version 4.1(3h) is affected.
- Version 4.2(2a) is affected.
- Version 4.1(3i) is affected.
- Version 4.2(2f) is affected.
- Version 4.2(2g) is affected.
- Version 4.2(3b) is affected.
- Version 4.1(3l) is affected.
- Version 4.2(3d) is affected.
- Version 4.3(1.230097) is affected.
- Version 4.2(1e) is affected.
- Version 4.2(1b) is affected.
- Version 4.2(1j) is affected.
- Version 4.2(1i) is affected.
- Version 4.2(1f) is affected.
- Version 4.2(1a) is affected.
- Version 4.2(1c) is affected.
- Version 4.2(1g) is affected.
- Version 4.3(1.230124) is affected.
- Version 4.1(2l) is affected.
- Version 4.2(3e) is affected.
- Version 4.3(1.230138) is affected.
- Version 4.2(3g) is affected.
- Version 4.3(2.230207) is affected.
- Version 4.2(3h) is affected.
- Version 4.2(3i) is affected.
- Version 4.3(2.230270) is affected.
- Version 4.1(3m) is affected.
- Version 4.1(2m) is affected.
- Version 4.3(2.240002) is affected.
- Version 4.3(3.240022) is affected.
- Version 4.2(3j) is affected.
- Version 4.1(3n) is affected.
- Version 4.3(2.240009) is affected.
- Version 4.3(3.240041) is affected.
- Version 4.2(3k) is affected.
- Version 4.3(3.240043) is affected.
- Version 4.3(4.240142) is affected.
- Version 4.3(2.240037) is affected.
- Version 4.3(2.240053) is affected.
- Version 4.3(4.240152) is affected.
- Version 4.2(3l) is affected.
- Version 4.3(2.240077) is affected.
- Version 4.3(4.242028) is affected.
- Version 4.3(4.241063) is affected.
- Version 4.3(4.242038) is affected.
- Version 4.2(3m) is affected.
- Version 4.3(2.240090) is affected.
- Version 4.3(5.240021) is affected.
- Version 4.3(2.240107) is affected.
- Version 4.3(4.242066) is affected.
- Version 4.2(3n) is affected.
- Version 4.3(5.250001) is affected.
- Version 4.2(3o) is affected.
- Version 4.3(2.250016) is affected.
- Version 4.3(2.250021) is affected.
- Version 4.3(5.250030) is affected.
- Version 4.3(2.250022) is affected.
- Version 4.3(6.250039) is affected.
- Version 4.3(6.250040) is affected.
- Version 4.3(5.250033) is affected.
- Version 4.3(6.250044) is affected.
- Version 4.3(6.250053) is affected.
- Version 4.3(2.250037) is affected.
- Version 4.3(2.250045) is affected.
- Version 4.3(4.252001) is affected.
- Version 4.3(4.252002) is affected.
- Version 6.0(1.250127) is affected.
- Version 4.2(3p) is affected.
- Version 6.0(1.250131) is affected.
- Version 4.3(6.250101) is affected.
- Version 6.0(1.250174) is affected.
- Version 4.3(6.250117) is affected.
- Version 4.3(5.250043) is affected.
- Version 4.3(5.250045) is affected.
- Version 4.3(6.250060) is affected.
- Version 6.0(1.250130) is affected.
- Version 4.3(4.241014) is affected.
- Version 6.0(1.251030) is affected.
- Version 4.3(2.250063) is affected.
- Version 6.0(1.250192) is affected.
- Version 4.3(6.260003) is affected.
- Version 6.0(1.250194) is affected.
- Version 6.0(1.260001) is affected.
- Version 4.3(6.260017) is affected.
- Version 4.3(2.260007) is affected.
- Version 6.0(2.260044) is affected.
- Version 6.0(2.260042) is affected.
- Version 4.0(1.260003) is affected.
- Version 2.0(2.260062) is affected.
- Version 2.0(1.250127) is affected.
- Version 2.0(1.250096) is affected.
- Version 4.0(1.260004) is affected.
- Version 6.0(2.260026) is affected.
- Version 6.0(1.251006) is affected.
- Version 1.2(0.250011) is affected.
- Version 1.1(0.250016) is affected.
- Version 1.0(0.240001) is affected.
- Version 1.0(0.250003) is affected.
- Version 1.2(0.250013) is affected.
- Version 1.1(0.250026) is affected.
- Version 1.0(1.250002) is affected.
- Version 1.1(0.250022) is affected.
- Version 1.1(0.250025) is affected.
- Version 1.0(1.250032) is affected.
- Version 6.0(2.260034) is affected.
- Version 6.0(2.260069) is affected.
- Version 4.3(6.260033) is affected.
- Version 2.0(2.260101) is affected.
- Version 4.2(3q) is affected.
- Version 4.2(3r) is affected.
- Version 1.2(0.260005) is affected.
- Version 4.11.1 is affected.
- Version 4.12.1 is affected.
- Version 4.12.2 is affected.
- Version 4.15.2 is affected.
- Version 4.15.3 is affected.
- Version 4.15.4 is affected.