On-Premises vs Cloud Vulnerability Management: Why Data Sovereignty Matters

When evaluating vulnerability management tools, one of the first decisions is deployment model: cloud-hosted SaaS or on-premises. For many European organizations, this isn’t just a technical preference — it’s a compliance requirement.

What data does a vulnerability management tool handle?

Before discussing deployment models, let’s be clear about what data is involved. A vulnerability management platform processes:

• Software inventory: Every application, version, and patch level on every endpoint in your organization
• Network topology: Which machines exist, their hostnames, IP addresses, operating systems
• Vulnerability matches: Which of your systems are vulnerable to which CVEs
• Remediation status: Who acknowledged what, when, and what actions were taken
• User information: Names, roles, and access levels of people using the platform

This is not trivial data. Your software inventory is effectively a map of your attack surface. In the wrong hands, it tells an attacker exactly which vulnerabilities to target and where.

The case for on-premises

Data never leaves your network

With an on-premises deployment, your inventory data, vulnerability matches, and remediation records stay on your infrastructure. No API calls to external servers carrying your asset data. No cloud storage of your vulnerability posture. The data exists on hardware you control.

Regulatory compliance

Several regulatory frameworks either require or strongly prefer on-premises processing of sensitive operational data. Swiss financial regulation (FINMA circulars), German banking regulation (BaFin’s BAIT/VAIT), and sector-specific requirements for healthcare, defense, and critical infrastructure all impose restrictions on where operational data can be processed.

GDPR Article 28 requires data controllers to ensure that processors provide sufficient guarantees. When your vulnerability management tool is self-hosted, you are the processor — the compliance chain is simpler.

Air-gapped environments

Some environments — defense contractors, critical infrastructure operators, classified networks — cannot have any internet connectivity. Cloud-based tools are simply not an option. On-premises tools that support air-gapped operation (with manual feed updates) are the only choice.

No vendor lock-in on data

With a self-hosted platform, your data is in a database on your server. You can back it up, migrate it, or query it directly. With SaaS tools, your data is in the vendor’s cloud, accessible only through their API, subject to their retention policies, and gone if you cancel your subscription.

The case for cloud

Cloud-based vulnerability management tools have genuine advantages. They require zero infrastructure management, updates are automatic, and they scale effortlessly. For organizations without a dedicated IT team or server infrastructure, SaaS can be the pragmatic choice.

Tools like Qualys VMDR, Rapid7 InsightVM (cloud version), and CrowdStrike Spotlight operate as SaaS platforms. They’re well-suited for organizations that are comfortable with cloud processing and don’t face strict data residency requirements.

The hybrid reality

Most organizations end up somewhere in the middle. The vulnerability scanner might be cloud-hosted, but the asset inventory stays on-premises. Or the management platform is SaaS, but agents collect data locally and only send summaries.

The key question isn’t “cloud or on-premises?” but rather: where does your sensitive operational data reside, and who can access it?

SentriKat’s approach: 100% on-premises, zero compromise

SentriKat was designed from the ground up as an on-premises platform. Every component — the FastAPI application, the PostgreSQL database, the nginx reverse proxy — runs in Docker containers on your infrastructure. The only outbound connections are to:

1. CISA KEV feed (public JSON, no authentication) — to download the vulnerability catalog
2. NVD API (public, optional API key) — to enrich CVE data with CVSS scores
3. Vendor advisory feeds (OSV.dev, Red Hat, Microsoft MSRC, Debian) — to detect vendor patches

None of these connections send any of your data outward. They only download public vulnerability information. Your software inventory, vulnerability matches, and remediation records never leave your network.

For fully air-gapped environments, SentriKat supports offline operation with manual feed imports.

Deployment comparison

Aspect	Cloud/SaaS	On-Premises (SentriKat)
Setup time	Minutes (sign up)	Minutes (docker compose up)
Infrastructure needed	None	1 server, 2GB RAM
Data location	Vendor’s cloud	Your infrastructure
Internet required	Always	Only for feed downloads
Air-gap support	No	Yes
Vendor data access	Yes	No
GDPR complexity	DPA required	You are the controller and processor
Typical cost	€15,000-50,000/yr	€2,499/yr

Making the decision

If your organization handles sensitive data, operates in a regulated industry, or simply believes that a map of your attack surface shouldn’t live on someone else’s servers, on-premises vulnerability management is the right choice.

Request a demo of SentriKat to see how on-premises deployment works in practice — from docker compose up to your first vulnerability match in under 10 minutes.

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SentriKat is a Swiss on-premises vulnerability management platform. Your data stays yours. Always.