CVE-2026-52817: Linuxfabrik Monitoring Plugins Sudoers May Be Able To Vulnerability

HIGH
Advisory Identifier: GHSA-8w6w-23mq-h8rg
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CWE-88
Published
Advisory Summary

CVE-2026-52817 is a HIGH sudoers may be able to vulnerability (CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')) affecting Linuxfabrik Monitoring Plugins libraries in the PyPI ecosystem. The issue involves sudoers may be able to obtain privilege escalation via /usr/bin/apt-get arguments. Remediation is available by upgrading affected packages to version 5.1.0.

CVE-2026-52817 at a Glance

CVE Identifier CVE-2026-52817
GHSA Identifier GHSA-8w6w-23mq-h8rg
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Affected Product Linuxfabrik Monitoring Plugins
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-52817

To remediate this vulnerability, upgrade all affected Linuxfabrik Monitoring Plugins dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

linuxfabrik-lib fixed: 5.1.0 
pip install linuxfabrik-lib>=5.1.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show linuxfabrik-lib

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-52817, inspect your installed packages using pip:

pip show linuxfabrik-lib

Analyze the terminal output to locate any version of Linuxfabrik Monitoring Plugins in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.1.0), your application is affected.

Note: The pip show linuxfabrik-lib command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'), where the product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. In Linuxfabrik Monitoring Plugins, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary In the [Debian.sudoers](https://github.com/Linuxfabrik/monitoring-plugins/blob/main/assets/sudoers/Debian.sudoers) file, `apt-get` is allowed for the nagios user. The full command including the arguments are not enforced and can therefore be choosen arbitrarily. This allows to easily get a root shell as the nagios user: ### PoC By choosing a particular argument, you can get (as a nagios user) a root shell: ``` sudo apt-get update -o APT::Update::Pre-Invoke::="/bin/sh" ``` Since the nagious user can use sudo to run apt-get as root, the resulting shell is also running as root. ### Impact The vulnerability is a local privilege escalation, impacting users who use the provided sudoers file. It requires that an attacker already compromised the nagios account (which is quite a high barrier to be honest). ### Fix Since only one place where `apt-get` is currently used (in [deb-updates](https://github.com/Linuxfabrik/monitoring-plugins/blob/998302a5fb43e89df1359f4cbb6558f81c96ae4f/check-plugins/deb-updates/deb-updates#L124)) was found, it should be enough to allow only the specific arguments used there. Here an example how the line in the sudoers file could look like: ``` /usr/lib64/nagios/plugins/strongswan-connections,\ /usr/lib64/nagios/plugins/systemd-unit,\ /usr/bin/apt-get update --quiet 2 ```

CVE-2026-52817 Affected Linuxfabrik Monitoring Plugins Versions

1 component(s)
Fixed Versions:
5.1.0
Product / Package Ecosystem Affected Versions Fixed Version
linuxfabrik-lib
pypi/linuxfabrik-lib
PyPI
< 5.1.0
5.1.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Linuxfabrik/monitoring-plugins/security/advisories/GHSA-8w6w-23mq-h8rg
Linuxfabrik Monitoring Plugins Source Repository REPOSITORY
https://github.com/Linuxfabrik/monitoring-plugins

Frequently Asked Questions

What is CVE-2026-52817?
CVE-2026-52817 is a security vulnerability in Linuxfabrik Monitoring Plugins involving Sudoers may be able to obtain privilege escalation via /usr/bin/apt-get arguments under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection').
Which Linuxfabrik Monitoring Plugins versions are affected?
Affected versions include releases prior to 5.1.0 across affected packages: linuxfabrik-lib.
What version fixes CVE-2026-52817?
Upgrading to 5.1.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is linuxfabrik-lib affected?
Yes, linuxfabrik-lib is affected in releases prior to 5.1.0. Upgrade your dependency to 5.1.0 or later.
What CWE is associated with CVE-2026-52817?
CVE-2026-52817 is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') (The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.).
How can I check PyPI dependencies for CVE-2026-52817?
Run the dependency tree command: 'pip show linuxfabrik-lib'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8w6w-23mq-h8rg",
  "modified" : "2026-07-02T20:23:56Z",
  "published" : "2026-07-02T20:23:56Z",
  "aliases" : [ "CVE-2026-52817" ],
  "summary" : "Linuxfabrik Monitoring Plugins: Sudoers may be able to obtain privilege escalation via /usr/bin/apt-get arguments",
  "details" : "### Summary\nIn the [Debian.sudoers](https://github.com/Linuxfabrik/monitoring-plugins/blob/main/assets/sudoers/Debian.sudoers) file, `apt-get` is allowed for the nagios user. The full command including the arguments are not enforced and can therefore be choosen arbitrarily. This allows to easily get a root shell as the nagios user:\n\n### PoC\nBy choosing a particular argument, you can get (as a nagios user) a root shell:\n```\nsudo apt-get update -o APT::Update::Pre-Invoke::=\"/bin/sh\"\n```\nSince the nagious user can use sudo to run apt-get as root, the resulting shell is also running as root.\n\n### Impact\nThe vulnerability is a local privilege escalation, impacting users who use the provided sudoers file. It requires that an attacker already compromised the nagios account (which is quite a high barrier to be honest).\n\n### Fix\nSince only one place where `apt-get` is currently used (in [deb-updates](https://github.com/Linuxfabrik/monitoring-plugins/blob/998302a5fb43e89df1359f4cbb6558f81c96ae4f/check-plugins/deb-updates/deb-updates#L124)) was found, it should be enough to allow only the specific arguments used there.\n\nHere an example how the line in the sudoers file could look like:\n```\n                    /usr/lib64/nagios/plugins/strongswan-connections,\\\n                    /usr/lib64/nagios/plugins/systemd-unit,\\\n                    /usr/bin/apt-get update --quiet 2\n```",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "linuxfabrik-lib"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.1.0"
      } ]
    } ],
    "database_specific" : {
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    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Linuxfabrik/monitoring-plugins/security/advisories/GHSA-8w6w-23mq-h8rg"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Linuxfabrik/monitoring-plugins"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-88" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T20:23:56Z",
    "nvd_published_at" : null
  }
}