---
id: CVE-2025-20143
title: Cisco IOS XR Software Secure Boot Bypass Vulnerability (CVE-2025-20143)
summary: >-
  A vulnerability in the boot process of Cisco IOS XR Software could allow an
  authenticated, local attacker with high privileges to bypass the Secure Boot
  functionality and load unverified software on an affected device. To exploit
  this vuln…
severity: medium
cvss: 6.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
vendor: Cisco
product: Cisco IOS XR Software
affected:
  - ios_xr_software
published: '2025-03-12'
updated: '2025-03-12'
sourceUpdated: '2025-03-12T16:00:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-lkm-zNErZjbZ
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-lkm-zNErZjbZ
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00111
epssPercentile: 0.01202
ingestedAt: '2026-10-06T08:05:42.481Z'
---

## Overview

A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker with high privileges to bypass the Secure Boot functionality and load unverified software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device.

This vulnerability is due to insufficient verification of modules in the software load process. An attacker could exploit this vulnerability by manipulating the loaded binaries to bypass some of the integrity checks that are performed during the booting process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass the requirement to run Cisco-signed images or alter the security properties of the running system.

Note: This vulnerability affects Cisco IOS XR Software, not the Secure Boot feature.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.



This advisory is part of the March 2025 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2025 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75548"].

## Vendor advisories

- **cisco-sa-sb-lkm-zNErZjbZ** · Cisco · affected: Cisco IOS XR Software · updated 2025-03-12 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-lkm-zNErZjbZ)

**Cisco IOS XR Software Secure Boot Bypass Vulnerability**. Released 2025-03-12.

Affected:

- Cisco IOS XR Software

## Remediation

Cisco has released software updates that address this vulnerability. https://software.cisco.com