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CRITICAL severity

CVE-2026-20267 — Cisco IOS XE

CRITICAL

CVE-2026-20267 is a critical-severity (CVSS 9) CWE-284 vulnerability in cisco ios xe. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

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…

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-20267.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk
0.00%0.29%0.59%0.88%0.4%0.4%Oct 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

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 software hardening releases that address multiple internally discovered vulnerabilities.

The vulnerabilities tracked by CVE-2026-20267 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-284. 

Affected Products

1 product · 267 configurations
OS
ios xecisco
267 versions
16.6.216.6.316.6.416.6.4a16.6.4s16.6.516.6.5a16.6.5b16.6.616.6.716.6.7a16.6.8

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every cisco ios xe deployment and check each version against the affected-products list above.

  2. Remediation status

    The records we use list no fixed version for CVE-2026-20267. Check the cisco ios xe advisory for a patched release, and apply the workarounds below until you can upgrade.

  3. Mitigate without a patch

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

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 software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20267 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-284. 
O3 Security · Runtime Protection

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CVE-2026-20267: Cisco IOS XE (Critical 9)