Vulnerability · Published Aug 5, 2026 · Assigned by cisco
CVE-2026-20311Cisco IOS XE Software Web UI Denial of Service Vulnerability
Medium 6.3
In plain English
A medium-severity security flaw in Cisco IOS XE Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Official description
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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco IOS XE Software | 17.3.117.3.1a17.3.2a17.3.1w17.3.217.4.117.4.1a17.3.1x |
Weakness: CWE-126 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H