Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character-substitution filter that omits semicolons, pipes, and non-space IFS whitespace characters before passing them to a grep command run via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required High

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact total

Affected Vendors & Products

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://www.nagios.com/security-disclosures/nagios-xi/2026r2/ cve-icon cve-icon
https://www.vulncheck.com/advisories/nagios-xi-2026r2-os-command-injection-via-mibs-php cve-icon cve-icon
History

Tue, 03 Nov 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 03 Nov 2026 15:00:00 +0000

Type Values Removed Values Added
Description Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character deny-list that omits semicolons and pipes before passing them to a grep command executed via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user. Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character-substitution filter that omits semicolons, pipes, and non-space IFS whitespace characters before passing them to a grep command run via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user.

Tue, 03 Nov 2026 13:45:00 +0000

Type Values Removed Values Added
Description Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character deny-list that omits semicolons and pipes before passing them to a grep command executed via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user.
Title Nagios XI < 2026R2 OS Command Injection via mibs.php
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-03T16:00:18.389Z

Reserved: 2026-10-30T15:31:52.079Z

Link: CVE-2026-119742

cve-icon Vulnrichment

Updated: 2026-11-03T15:59:11.434Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-03T14:17:34.843

Modified: 2026-11-03T16:25:21.310

Link: CVE-2026-119742

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-03T14:30:08Z

Weaknesses