8.6
HIGH CVSS 4.0
CVE-2026-119742
Nagios XI < 2026R2 OS Command Injection via mibs.php
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.

INFO

Published Date :

Nov. 3, 2026, 2:17 p.m.

Last Modified :

Nov. 3, 2026, 2:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-119742 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update Nagios XI to version 2026R2 or later to fix OS command injection.
  • Update Nagios XI to version 2026R2 or later.
  • Apply security patches provided by the vendor.
  • Review file upload sanitization logic.
  • Restrict administrator privileges.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-119742.

URL Resource
https://www.nagios.com/security-disclosures/nagios-xi/2026r2/
https://www.vulncheck.com/advisories/nagios-xi-2026r2-os-command-injection-via-mibs-php
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-119742 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-119742 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-119742 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Nov. 03, 2026

    Action Type Old Value New Value
    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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-78
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/119xxx/CVE-2026-119742.json">CVE-2026-119742</a>
    Added Reference https://www.nagios.com/security-disclosures/nagios-xi/2026r2/
    Added Reference https://www.vulncheck.com/advisories/nagios-xi-2026r2-os-command-injection-via-mibs-php
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.