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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Cisco Cisco IOS XE Software unknown
Version Status Constraints
17.2.1a affected —
16.12.1y affected —
16.12.3s affected —
16.7.1b affected —
16.6.2 affected —
16.6.5 affected —
16.12.1w affected —
16.9.1d affected —
17.3.1 affected —
16.9.4c affected —
16.7.1 affected —
17.2.1 affected —
16.6.8 affected —
16.9.1b affected —
16.9.2s affected —
16.12.4 affected —
16.12.3a affected —
17.1.1s affected —
16.11.1a affected —
16.7.2 affected —
16.11.1b affected —
16.9.1s affected —
16.9.3h affected —
16.9.1c affected —
16.6.5a affected —
16.6.3 affected —
16.10.1f affected —
17.2.1v affected —
16.8.1e affected —
16.9.3a affected —
16.12.1a affected —
16.12.1x affected —
16.6.4s affected —
16.10.1c affected —
16.12.3 affected —
16.11.2 affected —
16.6.5b affected —
16.12.2s affected —
16.10.1b affected —
16.7.3 affected —
16.6.7 affected —
16.9.6 affected —
16.9.2 affected —
16.10.1 affected —
16.12.1t affected —
16.9.1 affected —
16.8.1a affected —
16.9.3s affected —
16.6.7a affected —
16.12.2 affected —
16.11.1 affected —
16.9.3 affected —
16.11.1s affected —
16.12.1 affected —
17.1.1 affected —
17.1.2 affected —
16.10.1d affected —
17.1.1t affected —
16.9.4 affected —
16.8.3 affected —
16.12.2t affected —
16.9.5 affected —
16.8.1s affected —
16.10.1e affected —
16.8.2 affected —
16.6.4 affected —
16.8.1b affected —
16.10.1a affected —
16.12.1z affected —
16.8.1c affected —
16.9.1a affected —
16.9.5f affected —
16.6.4a affected —
16.10.1g affected —
16.8.1 affected —
16.6.6 affected —
16.9.2a affected —
16.8.1d affected —
16.10.3 affected —
16.7.1a affected —
16.11.1c affected —
16.10.1s affected —
17.2.1r affected —
17.1.1a affected —
16.10.2 affected —
16.12.2a affected —
16.12.1c affected —
16.12.1s affected —
16.7.4 affected —
17.2.2 affected —
16.9.8 affected —
16.9.7 affected —
17.1.3 affected —
17.3.1a affected —
17.3.2a affected —
16.12.5 affected —
17.3.1w affected —
17.3.2 affected —
17.4.1 affected —
16.12.4a affected —
17.4.1a affected —
17.3.1x affected —
17.3.3 affected —
16.6.9 affected —
17.2.3 affected —
17.5.1 affected —
16.12.1z1 affected —
16.12.5a affected —
17.4.1b affected —
17.3.1z affected —
16.12.5b affected —
17.4.2 affected —
17.3.3a affected —
17.3.5 affected —
17.3.4 affected —
17.5.1a affected —
16.12.6 affected —
17.6.1 affected —
16.12.1z2 affected —
16.6.10 affected —
17.3.4a affected —
17.6.1a affected —
17.7.1 affected —
17.6.1x affected —
17.6.2 affected —
16.12.6a affected —
17.3.4c affected —
17.4.2a affected —
17.3.4b affected —
17.7.1a affected —
16.12.7 affected —
17.8.1a affected —
17.6.3a affected —
17.6.3 affected —
17.7.2 affected —
17.7.1b affected —
17.9.1w affected —
17.3.5a affected —
17.6.1z affected —
16.12.8 affected —
17.8.1 affected —
17.9.1 affected —
17.6.4 affected —
17.3.5b affected —
17.9.1a affected —
17.3.6 affected —
17.10.1 affected —
16.9.8a affected —
17.6.1z1 affected —
17.10.1a affected —
17.9.2 affected —
17.6.5 affected —
17.9.1x affected —
17.9.1y affected —
16.9.8b affected —
17.3.7 affected —
17.9.2a affected —
17.9.3 affected —
16.12.9 affected —
17.11.1 affected —
17.10.1b affected —
17.6.6 affected —
17.9.1x1 affected —
17.11.1a affected —
17.9.3a affected —
17.12.1 affected —
17.3.8 affected —
17.9.4 affected —
16.12.10 affected —
17.12.1w affected —
17.9.1y1 affected —
17.12.1a affected —
17.9.5 affected —
17.13.1 affected —
17.12.1x affected —
17.12.2 affected —
17.14.1 affected —
17.9.4a affected —
17.3.8a affected —
17.6.6a affected —
17.6.5a affected —
17.6.7 affected —
16.12.10a affected —
17.15.1 affected —
17.13.1a affected —
17.12.2a affected —
16.12.11 affected —
17.12.3 affected —
17.12.1y affected —
17.12.1z affected —
17.9.5a affected —
17.14.1a affected —
17.9.5b affected —
17.6.8 affected —
16.12.12 affected —
17.12.4 affected —
17.9.6 affected —
17.17.1 affected —
17.16.1 affected —
17.15.1w affected —
17.12.3a affected —
17.9.5c affected —
17.15.1a affected —
17.12.1z1 affected —
17.15.2 affected —
17.15.1b affected —
17.9.5d affected —
17.15.1x affected —
17.9.6a affected —
17.12.1z2 affected —
17.6.8a affected —
17.16.1a affected —
16.12.13 affected —
17.15.3 affected —
17.9.7 affected —
17.12.5 affected —
17.15.1y affected —
17.9.5e affected —
17.12.4a affected —
17.15.2a affected —
17.15.2c affected —
17.15.2b affected —
17.12.1z3 affected —
17.9.5f affected —
17.12.4b affected —
17.12.5a affected —
17.18.1 affected —
17.12.6 affected —
17.12.1z4 affected —
17.9.8 affected —
17.9.7a affected —
17.15.3a affected —
17.15.4 affected —
17.12.5b affected —
17.15.3b affected —
16.12.14 affected —
17.18.1z affected —
17.9.7b affected —
17.12.5c affected —
26.1.1 affected —
17.18.1a affected —
17.15.4a affected —
17.18.2 affected —
17.18.1w affected —
17.15.4b affected —
17.12.6a affected —
17.12.7 affected —
17.15.4c affected —
17.9.9 affected —
17.12.5d affected —
16.12.15 affected —
17.15.4s1 affected —
17.15.5 affected —
17.12.1z5 affected —
17.18.1x affected —
17.12.1z6 affected —
17.15.4d affected —
17.12.6b affected —
17.4.1c affected —
17.15.5a affected —
17.18.1y affected —
17.12.7a affected —
17.18.3 affected —
17.12.7b affected —
17.18.3a affected —
26.1.1a affected —
17.15.7 affected —
16.12.16 affected —

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxe-V8NMuMZJ cve-icon
History

Wed, 05 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 05 Aug 2026 17:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Cisco IOS XE Software Security Hardening Release
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-08-05T17:45:14.130Z

Reserved: 2025-10-08T11:59:15.403Z

Link: CVE-2026-20273

cve-icon Vulnrichment

Updated: 2026-08-05T17:39:09.576Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses