Is there a free vulnerability scanner for Linux?

Yes. TridentStack Control scans Linux servers and desktops for known vulnerabilities in installed packages. Your first 200 endpoints are free forever, including for commercial use.

Does it handle backported security fixes?

Yes. Findings are matched against each distribution's security advisories, which record the exact package release that fixes a CVE. A package that was patched by a backport is not reported as vulnerable.

Does it need SSH access or root credentials?

No. A lightweight agent runs on each machine and connects outbound. There are no credentials to distribute and no inbound access to allow.

No. TridentStack Control is a hosted commercial platform that is free for your first 200 endpoints. If you need an open-source scanner you host yourself, OpenVAS and Wazuh are the usual choices, and the table above shows how they differ.

Can it install the fixed packages?

Yes. When the endpoint's repositories offer a version that fixes the CVE, you can install it from the console through the system's own package manager.

Free Vulnerability Scanner for Linux

A lightweight agent that matches the packages installed on each Linux server or desktop against that distribution's own security advisories. Covers Ubuntu, Debian, RHEL, CentOS Stream, Rocky Linux, AlmaLinux, and Amazon Linux. 200 endpoints free forever, commercial use allowed.

Start free See the pricing calculator

What the free scanner shows you

A live TridentStack Control demo on sample data. Pick a scene or let it play. There are no paid add-ons: everything shown here is included free for your first 200 endpoints.

Every CVE in the fleet, narrowed to CISA's Known Exploited list, then to critical severity.

See a sample report

Why Linux scanning depends on the distribution

Linux distributions backport security fixes. Ubuntu, Debian, and Red Hat routinely patch a vulnerability in an older package version without changing the upstream version number, so a scanner that compares version strings against a generic CVE list reports problems that were fixed long ago and misses the ones that matter.

The reliable answer comes from each distribution's own security advisories, which state the exact package release that fixes each CVE on each release of the distribution. That is the data TridentStack Control matches against, so a finding means the installed package is older than the fixed one.

Free vulnerability scanners for Linux, compared

The main free ways to find vulnerabilities on Linux servers and desktops today, checked against each source page.

Tool	Free limit	How it scans	Ties to patching	The catch
TridentStack Control	200 endpoints, forever	Agent on each endpoint, continuous	Yes	$5/endpoint/mo past 200, commercial use fine
Action1	200 endpoints, forever	Agent on each endpoint, continuous	Yes	Its documentation lists Linux vulnerability assessment as unsupported
Nessus Essentials (Tenable)	Up to 5 IPs, 30-day license	Network scan you launch, point-in-time	No	Non-commercial use only; 30-day-delayed feed; no reporting or export on free
OpenVAS / Greenbone CE	Free/OSS, no seat cap	Network scan from a scanner you host	No	Community Feed only; the free appliance drops schedules, notifications, and backups; forum support
Wazuh	Free/OSS, self-hosted	Agent on each endpoint, continuous	No	A broad XDR and SIEM you self-host and operate; managed Wazuh Cloud is paid
Trivy (Aqua)	Free/OSS, no cap	Command-line scan of images, filesystems, and repositories	No	Scans build artifacts, not a continuous endpoint agent; no fleet dashboard or scheduling

Free offers verified against each vendor's own page.

What you get free on Linux

Every capability below is included for your first 200 endpoints, at no cost, for production use.

Matched to distribution advisories

Findings come from each distribution's own security data, so backported fixes are recognized and are not reported as open.

Package-level detail

Each finding names the installed package, its version, and the fixed version, so you know exactly what an update will change.

Ranked by real exploitation risk

Each CVE carries its CVSS severity, EPSS exploit-prediction score, and CISA KEV status, so the short list for today is obvious.

Continuous, with no scan windows

The agent reports package inventory as it changes. There is no scanner to schedule and no SSH credentials to distribute.

Fix from the same console

Install the fixed package through the system's own package manager, on demand or on a schedule, from the page that reported the CVE.

Servers, desktops, and cloud instances

The same agent covers physical servers, virtual machines, and cloud instances, alongside your Windows and macOS endpoints.

When you outgrow free

Past your first 200 endpoints it is $5 per endpoint per month, with lower per-endpoint rates past 500 endpoints and every feature still included. See the pricing calculator.

Vulnerability scanning for Ubuntu and Debian

On Ubuntu 20.04 and later and Debian 12 and later, the agent reads the installed package list and compares it against the distribution's security advisories for that release. A finding shows the package, the installed version, and the version that fixes it.

When the fixed package is available from the endpoint's configured repositories, it can be installed from the console. When the repositories do not offer it yet, the finding says so, so you are not chasing an update that does not exist.

Vulnerability scanning for RHEL, Rocky Linux, AlmaLinux, and Amazon Linux

Red Hat Enterprise Linux and its compatible rebuilds keep the same package version for years and backport fixes into new releases of it. The agent matches RHEL 8 and later, CentOS Stream, Rocky Linux, AlmaLinux, and Amazon Linux 2 and later against vendor advisory data, which is the only way to read those backports correctly.

Fixes install through the system's own package manager, so an update lands exactly as the distribution intends.

A scanner for Linux servers that does not need SSH access

Credentialed network scans of Linux servers need an account on every machine and a route to it. Both are things most teams are trying to reduce. An agent connects outbound, runs locally, and needs neither.

It also means a server that was powered off or unreachable during a scan window is not silently missing from the report. Each endpoint reports when it is online, and the dashboard shows when it last did.

Frequently asked questions

Log 01
Log 01
Is there a free vulnerability scanner for Linux?
Yes. TridentStack Control scans Linux servers and desktops for known vulnerabilities in installed packages. Your first 200 endpoints are free forever, including for commercial use.
Log 02
Log 02
Which Linux distributions are covered?
Vulnerability detection covers Ubuntu, Debian, RHEL, CentOS Stream, Rocky Linux, AlmaLinux, and Amazon Linux, each matched against its own advisory data.
Log 03
Log 03
Does it handle backported security fixes?
Yes. Findings are matched against each distribution's security advisories, which record the exact package release that fixes a CVE. A package that was patched by a backport is not reported as vulnerable.
Log 04
Log 04
Does it need SSH access or root credentials?
No. A lightweight agent runs on each machine and connects outbound. There are no credentials to distribute and no inbound access to allow.
Log 05
Log 05
Is it open source?
No. TridentStack Control is a hosted commercial platform that is free for your first 200 endpoints. If you need an open-source scanner you host yourself, OpenVAS and Wazuh are the usual choices, and the table above shows how they differ.
Log 06
Log 06
Can it install the fixed packages?
Yes. When the endpoint's repositories offer a version that fixes the CVE, you can install it from the console through the system's own package manager.

Start scanning Linux, free

200 endpoints free forever, every feature included. No credit card, no time limit.

Start free See everything in TridentStack Control

Competitor facts verified against each vendor page. Last verified 2026-09-23. Reviewed by Adam Curtis, Founder, TridentStack.