Ios Xr
CVE-2026-20040
HIGH
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticate with low-privileged account
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ExploitCraft malicious CLI command with unvalidated arguments
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ExecutionBypass input validation in command parser
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ImpactExecute arbitrary OS commands as root
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization OS command sanitization, avoid shell exec
MITRE ATT&CK
2 techniques across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Local console or SSH access with valid low-privileged credentials to Cisco IOS XR CLI; affected device with vulnerable CLI command processing enabled in default configuration. |
| Impact | CVSS 8.8 (HIGH). Attack vector: Local. Complexity: Low. Privileges required: Low. User interaction: None. Exploitation requires authentication. Exploitable via local access. |
| Exploit ScenarioDerived | An attacker (requires authentication) could exploit this vulnerability to elevate privileges to root and execute arbitrary commands on the underlying oper. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Insufficient CLI argument validation in Cisco IOS XR Software enables authenticated local attackers to achieve root-level code execution through crafted commands. An attacker with low-privileged account access can exploit this vulnerability to bypass privilege restrictions and execute arbitrary commands on the affected device's underlying operating system. No patch is currently available for this high-severity vulnerability.
Earlier versions of this analysis (1)
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. [CVSS 8.8 HIGH]
RemediationAI
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Affects your stack
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Technical ContextAI · show details
Classified as CWE-78 (OS Command Injection). Affects CLI of Cisco IOS XR Software. 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
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from Vendor (cisco) · only source for this CVE.
CVSS VectorVendor: cisco
DescriptionCVE.org
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.
Executive ViewAI
A critical vulnerability in Cisco IOS XR CLI allows authenticated local users to gain root-level command execution on affected network devices. This poses significant risk to organizations relying on Cisco infrastructure, as compromised devices could enable lateral movement, data exfiltration, and network disruption. Immediate action is required to identify affected systems and implement compensating controls until patches become available.
Restrict local CLI access to authorized personnel only through role-based access control (RBAC); disable unnecessary command-line interfaces and management protocols; implement session logging and monitoring for all local administrative activity; enforce strong authentication and account lockout policies; segment network access so compromised devices cannot laterally move to critical systems; consider disabling local authentication in favor of centralized authentication (AAA/TACACS+/RADIUS) where supported; maintain offline backups of critical configurations.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
OS command injection occurs when an application passes unsanitized user input directly into system shell commands.
Affected Products (CPE)CVE.org
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GitHub PoC
Exploit-DB