High severity · published Mar 11, 2026
CVE-2026-20040
Cisco IOS XR Software CLI Privilege Escalation Vulnerability
8.8
CVSS
0.2%
EPSS
No
On KEV
Description
A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user arguments that are passed to specific CLI commands. An attacker with a low-privileged account could exploit this vulnerability by using crafted commands at the prompt. A successful exploit could allow the attacker to elevate privileges to root and execute arbitrary commands on the underlying operating system.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CI
Cisco IOS XR Software · Cisco
6.5.3; 6.5.29; 6.5.1; 6.6.1; 6.5.2; 6.5.92; +34 more · source: vendor
IX
Ios XR · Cisco
before 25.2.21; 25.3.1 before 25.4.2 · source: NVD
Affected product
CI
Cisco IOS XR Software
Cisco
More from Cisco IOS XR Software
8.8
CVE-2020-3118
Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability
8.6
CVE-2020-3569
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities
8.6
CVE-2020-3566
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
6.5
CVE-2022-20821
Cisco IOS XR Software Health Check Open Port Vulnerability
9.8
CVE-2026-20279
Cisco IOS XR Software Security Hardening Release: September 2026