CVE-2026-20104
published 2026-03-25CVE-2026-20104: A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco…
PriorityP434medium6.1CVSS 3.1
AVPACLPRNUINSUCHIHAN
EPSS
0.16%
5.8th percentile
A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugged Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute arbitrary code at boot time and break the chain of trust.
This vulnerability is due to insufficient validation of software at boot time. An attacker could exploit this vulnerability by manipulating the loaded binaries on an affected device to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to execute code that bypasses the requirement to run Cisco-signed images.
Cisco has assigned this security advisory a Security Impact Rating (SIR) of High rather than Medium as the score indicates because this vulnerability allows an attacker to bypass a major security feature of a device.
Affected
60 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
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| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
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| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
| cisco | cisco_ios_xe_software | — | — |
CVSS provenance
nvdv3.16.1MEDIUMCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
vendor_cisco6.1MEDIUM
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GHSA
GHSA-38h5-57rq-7mj8: A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, C
ghsa_unreviewed·2026-03-25
CVE-2026-20104 [MEDIUM] CWE-124 GHSA-38h5-57rq-7mj8: A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, C
A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugged Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute arbitrary code at boot time and break the chain of trust.
This vulnerability is due to insufficient validation of software at boot time. An attacker could exploit this vulnerability by manipulating the loaded binaries on an affected device to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to execute code th
Cisco
Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
vendor_cisco·2026-03-25·CVSS 6.1
CVE-2026-20104 [MEDIUM] CWE-124 Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugged Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute arbitrary code at boot time and break the chain of trust.
This vulnerability is due to insufficient validation of software at boot time. An attacker could exploit this vulnerability by manipulating the loaded binaries on an affected device to bypass some of the integrity checks that a
Cisco
Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
vendor_cisco·CVSS 3.1
CVE-2026-20104 Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
CVE-2026-20104: Cisco IOS XE Software for Cisco Catalyst and Rugged Series Switches Secure Boot Bypass Vulnerability
A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugged Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute arbitrary code at boot time and break the chain of trust. This vulnerability is due to insufficient validation of software at boot time. An attacker could exploit this vulnerability by manipulating the loaded binaries on an affected device to bypass some of the integrity
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-03-25
Published