Cisco IOS XR up to 25.4.1 CLI os command injection

Summaryinfo

A vulnerability identified as critical has been detected in Cisco IOS XR. Affected by this vulnerability is an unknown functionality of the component CLI. The manipulation leads to os command injection. This vulnerability is documented as CVE-2026-20040. The attack needs to be performed locally. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Cisco IOS XR. This issue affects some unknown functionality of the component CLI. The manipulation with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2026-20040 since 10/08/2025. The exploitation is known to be easy. Attacking locally is a requirement. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 03/14/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 302176 (Cisco IOS XR Software CLI Privilege Escalation (cisco-sa-iosxr-privesc-bF8D5U4W)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (302176), EUVD (EUVD-2026-11214) and CERT Bund (WID-SEC-2026-0706). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Cisco IOS XR

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XR

Version

• 6.5.1
• 6.5.2
• 6.5.3
• 6.5.15
• 6.5.25
• 6.5.26
• 6.5.28
• 6.5.29
• 6.5.31
• 6.5.32
• 6.5.33
• 6.5.35
• 6.5.90
• 6.5.92
• 6.5.93
• 6.5.351
• 6.5.352
• 6.5.353
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.11
• 6.6.12
• 6.6.25
• 6.7.1
• 6.7.2
• 6.7.3
• 6.7.4
• 6.7.35
• 6.8.1
• 6.8.2
• 6.9.1
• 6.9.2
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.11
• 7.0.12
• 7.0.14
• 7.0.90
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.15
• 7.1.25
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.12
• 7.3.1
• 7.3.2
• 7.3.3
• 7.3.4
• 7.3.5
• 7.3.6
• 7.3.15
• 7.3.16
• 7.3.27
• 7.4.1
• 7.4.2
• 7.4.15
• 7.4.16
• 7.5.1
• 7.5.2
• 7.5.3
• 7.5.4
• 7.5.5
• 7.5.12
• 7.5.52
• 7.6.1
• 7.6.2
• 7.6.3
• 7.6.15
• 7.7.1
• 7.7.2
• 7.7.21
• 7.8.1
• 7.8.2
• 7.8.12
• 7.8.22
• 7.8.23
• 7.9.1
• 7.9.2
• 7.9.21
• 7.10.1
• 7.10.2
• 7.11.1
• 7.11.2
• 7.11.21
• 24.1.1
• 24.1.2
• 24.2.1
• 24.2.2
• 24.2.11
• 24.2.20
• 24.2.21
• 24.3.1
• 24.3.2
• 24.3.20
• 24.3.30
• 24.4.1
• 24.4.2
• 24.4.10
• 24.4.15
• 24.4.30
• 25.1.1
• 25.1.2
• 25.1.30
• 25.2.1
• 25.2.2
• 25.2.15
• 25.2.30
• 25.3.1
• 25.3.15
• 25.4.1

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

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Entryinfo

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