Cisco IOS XR Software CLI Privilege Escalation (cisco-sa-iosxr-privesc-bF8D5U4W)

high Nessus Plugin ID 302176

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Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco IOS XR is affected by a vulnerability.

- 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. (CVE-2026-20040)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCwp27221, CSCwp30135, CSCwp30142, CSCwp30146, CSCwp30149, CSCwp32614, CSCwp32629, CSCwp33021, CSCwp33030, CSCwp33034, CSCwp35627, CSCwp84685, CSCws24696, CSCws24717, CSCws24740

Plugin Details

Severity: High

ID: 302176

File Name: cisco-sa-iosxr-privesc-bF8D5U4W-iosxr.nasl

Version: 1.1

Type: combined

Family: CISCO

Published: 3/13/2026

Updated: 3/13/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.3

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-20040

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:ios_xr

Required KB Items: Host/Cisco/IOS-XR/Version

Patch Publication Date: 3/11/2026

Vulnerability Publication Date: 3/11/2026

Reference Information

CVE: CVE-2026-20040

CISCO-SA: cisco-sa-iosxr-privesc-bF8D5U4W

IAVA: 2026-A-0242

CISCO-BUG-ID: CSCwp27221, CSCwp30135, CSCwp30142, CSCwp30146, CSCwp30149, CSCwp32614, CSCwp32629, CSCwp33021, CSCwp33030, CSCwp33034, CSCwp35627, CSCwp84685, CSCws24696, CSCws24717, CSCws24740

Detections

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