CiscoCVE-2026-20301
Cisco IOS XE Software: denial of service
No fix yet
A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as the External Client protocol, of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to improper handling of malformed XMCP packets. An attacker could exploit this vulnerability by sending a malformed XMCP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload unexpectedly, resulting in a DoS condition. The attacker does not need the XMCP client username to exploit this vulnerability.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Cisco IOS XE Software Product | <= 17.2.1a | No fix yet |
| <= 16.12.1y | No fix yet | |
| <= 16.12.3s | No fix yet | |
| <= 16.7.1b | No fix yet | |
| IOS Product | <= 15.2(7)E7 | No fix yet |
| <= 15.2(8)E3 | No fix yet | |
| <= 15.7(3)M10 | No fix yet | |
| <= 15.8(3)M9 | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-606