CVE-2026-52817

CVE-2026-52817 is a high-severity security vulnerability in linuxfabrik-lib (pip), affecting versions <= 5.0.0. It is fixed in 5.1.0.

Summary

Linuxfabrik Monitoring Plugins: Sudoers may be able to obtain privilege escalation via /usr/bin/apt-get arguments

In the 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).

Affected versions

linuxfabrik-lib (<= 5.0.0)

Security releases

linuxfabrik-lib → 5.1.0 (pip)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Since only one place where apt-get is currently used (in deb-updates) 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

Frequently Asked Questions

  1. What is CVE-2026-52817? CVE-2026-52817 is a high-severity security vulnerability in linuxfabrik-lib (pip), affecting versions <= 5.0.0. It is fixed in 5.1.0.
  2. Which versions of linuxfabrik-lib are affected by CVE-2026-52817? linuxfabrik-lib (pip) versions <= 5.0.0 is affected.
  3. Is there a fix for CVE-2026-52817? Yes. CVE-2026-52817 is fixed in 5.1.0. Upgrade to this version or later.
  4. Is CVE-2026-52817 exploitable, and should I be worried? Whether CVE-2026-52817 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
  5. What actually determines whether CVE-2026-52817 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
  6. How do I fix CVE-2026-52817? Upgrade linuxfabrik-lib to 5.1.0 or later.

Other vulnerabilities in linuxfabrik-lib

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