Cisco IOS XE Software Extensible Messaging Client Protocol DoS (cisco-sa-ios-xmcp-thbAr34t)

high Nessus Plugin ID 333312

Synopsis

The remote device is affected by a denial of service vulnerability.

Description

According to its self-reported version, Cisco IOS-XE Software is affected by a denial of service vulnerability. A flaw exists in the Extensible Messaging Client Protocol (XMCP) due to improper handling of malformed XMCP packets. An unauthenticated, remote attacker can exploit this issue, via a malformed XMCP packet, to cause the system to stop responding.

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug ID CSCwu20827

See Also

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwu20827

http://www.nessus.org/u?75851b9b

Plugin Details

Severity: High

ID: 333312

File Name: cisco-sa-ios-xmcp-thbAr34t-iosxe.nasl

Version: 1.1

Type: Combined

Family: CISCO

Published: 8/7/2026

Updated: 8/7/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 51.03

CVSS v2

Risk Factor: High

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-20301

CVSS v3

Risk Factor: High

Base Score: 8.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:/o:cisco:ios_xe

Required KB Items: Host/Cisco/IOS-XE/Version

Patch Publication Date: 8/5/2026

Vulnerability Publication Date: 8/5/2026

Reference Information

CVE: CVE-2026-20301

CWE: 606

CISCO-SA: cisco-sa-ios-xmcp-thbAr34t

IAVA: 2026-A-0807

CISCO-BUG-ID: CSCwu20827