---
id: CVE-2026-20273
title: >-
  As part of Cisco's ongoing commitment to proactive security and product
  quality, the Cisco IOS XE Software engineering team has conducted a
  comprehensive internal security review
summary: >-
  As part of Cisco's ongoing commitment to proactive security and product
  quality, the Cisco IOS XE Software engineering team has conducted a
  comprehensive internal security review. This review resulted in a software
  hardening release that…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-20
published: '2026-08-05'
updated: '2026-08-14'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20273'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxe-V8NMuMZJ
    label: psirt@cisco.com
  - url: >-
      https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://software.cisco.com'
tags:
  - nvd
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00467
epssPercentile: 0.3783
ingestedAt: '2026-08-15T17:27:28.041Z'
vendor: Cisco
product: Cisco IOS XE Software
affected:
  - ios_xe_software 3.2.0SG
  - ios_xe_software 3.2.1SG
  - ios_xe_software 3.7.0S
  - ios_xe_software 3.7.1S
  - ios_xe_software 3.3.0SG
  - ios_xe_software 3.7.2S
  - ios_xe_software 3.7.3S
  - ios_xe_software 3.7.4S
  - ios_xe_software 3.8.0S
  - ios_xe_software 3.8.1S
  - ios_xe_software 3.8.2S
  - ios_xe_software 3.9.1S
  - ios_xe_software 3.9.0S
  - ios_xe_software 3.2.0SE
  - ios_xe_software 3.3.0SE
  - ios_xe_software 3.2.1SE
  - ios_xe_software 3.2.2SE
  - ios_xe_software 3.2.3SE
  - ios_xe_software 3.2.2SG
  - ios_xe_software 3.2.3SG
  - ios_xe_software 3.2.4SG
  - ios_xe_software 3.2.5SG
  - ios_xe_software 3.3.2SG
  - ios_xe_software 3.4.0SG
  - ios_xe_software 3.4.2SG
  - ios_xe_software 3.3.1SG
  - ios_xe_software 3.4.1SG
  - ios_xe_software 3.3.1SE
  - ios_xe_software 3.5.0E
  - ios_xe_software 3.10.0S
  - ios_xe_software 3.10.1S
  - ios_xe_software 3.10.2S
  - ios_xe_software 3.10.0aS
  - ios_xe_software 3.11.1S
  - ios_xe_software 3.12.0S
  - ios_xe_software 3.11.2S
  - ios_xe_software 3.13.0S
  - ios_xe_software 3.10.3S
  - ios_xe_software 3.10.4S
  - ios_xe_software 3.7.5S
---

## Overview

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.

The vulnerabilities tracked by CVE-2026-20273 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-20.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **cisco-sa-hardening-iosxe-V8NMuMZJ** · Cisco · affected: Cisco IOS XE Software (595 versions) · updated 2026-08-05 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxe-V8NMuMZJ)