CVE-2026-20046 in IOS XR
Summary
by MITRE • 03/11/2026
A vulnerability in task group assignment for a specific CLI command in Cisco IOS XR Software could allow an authenticated, local attacker to elevate privileges and gain full administrative control of an affected device.
This vulnerability is due to incorrect mapping of a command to task groups within the source code. An attacker with a low-privileged account could exploit this vulnerability by using the CLI command to bypass the task group–based checks. A successful exploit could allow the attacker to elevate privileges and perform actions on an affected device without authorization checks.
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Analysis
by VulDB Data Team • 03/14/2026
This vulnerability exists within Cisco IOS XR Software where a specific command in the command line interface fails to properly validate task group assignments during execution. The flaw stems from improper mapping of CLI commands to their respective task groups in the software's source code implementation. When an authenticated local user with low privileges attempts to execute the affected command, the system incorrectly processes the task group permissions, allowing unauthorized privilege escalation. The vulnerability specifically targets the authorization framework that governs what actions users can perform based on their assigned task groups, which is a fundamental security control in network operating systems.
The technical exploitation of this vulnerability relies on the attacker's ability to leverage the misconfigured task group mappings to bypass the standard authorization checks that normally prevent privilege escalation. This represents a critical flaw in the software's access control mechanism, where the command execution flow does not properly enforce the security boundaries that separate different privilege levels. The vulnerability is particularly dangerous because it allows local attackers who already have authenticated access to the system to escalate their privileges without requiring additional authentication factors or complex attack vectors. The issue manifests as an authorization bypass where the system incorrectly grants elevated permissions to commands that should be restricted to administrative users.
From an operational perspective, this vulnerability poses significant risk to network infrastructure security as it enables attackers to gain full administrative control over affected Cisco IOS XR devices. The impact extends beyond simple privilege escalation since administrators may be able to execute arbitrary commands, modify system configurations, access sensitive data, and potentially disrupt network operations. The vulnerability affects the integrity and confidentiality of network devices, as unauthorized users could manipulate device settings, install malicious software, or create backdoors for persistent access. This type of local privilege escalation vulnerability is particularly concerning in network environments where administrative access is required for critical operations and where device compromise could lead to widespread service disruption.
Mitigation strategies should focus on applying the latest security patches provided by Cisco to address the specific task group mapping issue in the affected software versions. Network administrators should also implement strict access controls and monitor for unusual command execution patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-284 which addresses improper access control in software systems, and it relates to ATT&CK technique T1068 which covers privilege escalation through local exploits. Organizations should conduct immediate vulnerability assessments to identify affected devices and implement network segmentation to limit the potential impact of successful exploitation. Additionally, regular security audits of command privilege mappings and access control configurations should be performed to prevent similar issues from arising in other software components.