Unchecked Input for Loop Condition in Cisco IOS XE - CVE-2026-20301
Published: August 6, 2026
Vulnerability identifier: #VU141054
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20301
CWE-ID: CWE-606
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of malformed packets in the Extensible Messaging Client Protocol (XMCP) when processing XMCP traffic. A remote attacker can send a malformed XMCP packet to cause a denial of service.
Only devices with the XMCP Server feature enabled are vulnerable.
Affected software
Cisco IOS XE
How to mitigate CVE-2026-20301
Install security update from vendor's website.
Cisco IOS XE - addressed in versions 17.12.8, 17.15.6, 17.18.4