CVE-2026-20311: Cisco IOS XE Software Web UI Denial of Service Vulnerability

Published Aug 5, 2026
·
Updated

A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient error handling in the web-based management interface. An attacker could exploit this vulnerability by authenticating with a malformed certificate. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Affected Software

1 affected component
Cisco IOS XE Software Web UI

Event History

Aug 5, 2026
CVE Published
via MITRE·04:32 PM
Data Sourced
via MITRE·04:32 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:16 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2026-20311?

CVE-2026-20311 has a medium severity rating of 6.3.

2

What type of attack does CVE-2026-20311 allow?

CVE-2026-20311 allows an authenticated, remote attacker to execute a denial of service (DoS) attack.

3

What causes the vulnerability in CVE-2026-20311?

CVE-2026-20311 is caused by insufficient error handling in the web-based management interface of Cisco IOS XE Software.

4

Who is affected by CVE-2026-20311?

CVE-2026-20311 affects devices running Cisco IOS XE Software that utilize the web-based management interface.

5

How can I mitigate the risk of CVE-2026-20311?

To mitigate CVE-2026-20311, ensure that only privileged authenticated users have access to the web-based management interface and monitor for abnormal activity.

Contact

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