CVE intelligence

CVE-2026-20311

Vulnerability intelligence

Published Aug 5, 2026Sources checked Oct 27, 2026

6.3MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-20311 and is rated Medium severity with a CVSS score of 6.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Cisco Security Advisories guidance

Vendor revision: Aug 5, 2026

Cisco has released software updates that address this vulnerability.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-20311?

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.

Source: NVD