Legacy NAV Security Risks: Why Staying on Dynamics NAV Past 2026 Could Cost You Everything

If you’re still running Dynamics NAV, you’re not alone, and you’re not “behind” because you’re careless. Most NAV customers stayed because it’s stable, familiar, and deeply customized.

But here’s the uncomfortable truth: security doesn’t care that the system still works. The moment your NAV version leaves extended support, you’re effectively running business-critical software without a safety net.

That usually shows up in small warning signs first:

• Your IT team spends too much time babysitting servers and updates
• Auditors start asking uncomfortable questions
• Integrations feel brittle (Power BI, Outlook, APIs, modern auth)
• You’re relying on “we’ve been fine so far” as the main security strategy

And unfortunately, that strategy doesn’t hold up in 2026.

Dynamics NAV End-of-Support: What Microsoft’s Dates Really Mean

Microsoft has ended mainstream support for every NAV version. The remaining clock is extended support:

• NAV 2016: ends April 2026
• NAV 2017: ends 2027
• NAV 2018: ends 2028 (last NAV release)

After that, NAV won’t suddenly stop running, but new security vulnerabilities won’t be patched by Microsoft. So the risk increases every month you stay on it.

Your NAV Vulnerabilities

1) Unpatched Exploits Don’t Stay “Hypothetical.”

Security vulnerabilities in business software are found all the time. The difference between a manageable issue and a crisis is simple:

Can your vendor patch it fast?

For example, Microsoft disclosed CVE-2022-41127, a remote code execution vulnerability affecting on‑premises Dynamics NAV and Business Central (via WCF TCP). Supported versions received patches. Older or unsupported environments were left with limited options.

And that’s the real problem: once your NAV version is out of extended support, future vulnerabilities don’t get fixed unless you build your own workaround (and accept the risk that it’s incomplete).

2) Legacy Authentication = Easier Account Compromise

Many NAV environments still depend on older identity patterns: basic Windows auth, shared accounts, weak password hygiene, and limited visibility.

What’s missing in many legacy setups:

• MFA (multi-factor authentication)
• Conditional access policies
• Modern identity monitoring and alerting
• Stronger controls for remote access and external users

In 2026, attackers don’t need “Hollywood hacking.”

3) Encryption and Data Protection Often Lag Behind Modern Expectations

A lot of on-prem NAV systems were designed in a time when perimeter security (firewalls + VPN) was considered “good enough.”

Today, auditors and regulators expect layered security:

• encryption at rest
• encryption in transit
• secure backups and recovery controls
• documented access control and audit trails

If NAV is holding sensitive customer, financial, payroll, or supplier data, the question becomes: If someone gets inside, how exposed is that data?

Compliance Risk: GDPR and Audit Exposure Gets Real After Support Ends

Running unsupported software isn’t automatically illegal, but it can be hard to defend during an audit.

Frameworks like GDPR, SOC 2, and industry standards generally expect you to use supported systems and apply security patches in a reasonable timeframe. If you can’t patch because your ERP is out of support, you may struggle to prove you’re meeting “appropriate technical measures” for protection.

GDPR fines can be up to €20M or 4% of annual global turnover (whichever is higher). Most businesses won’t ever hit the maximum, but the reputational and contractual damage from an audit failure can hurt just as much.

The Real Cost of Ignoring These Risks

Downtime Is the Part Nobody Budgets For

Even a “small” incident can create a big operational disruption:

• Finance close delayed
• Shipping and invoicing are blocked
• Purchase orders stuck
• Inventory out of sync
• Teams reverting to spreadsheets under pressure

You don’t just pay for IT recovery; you pay for lost productivity, delayed revenue, and customer churn.

Maintenance Costs Keep Climbing

As NAV gets older:

• Finding skilled NAV resources becomes harder and more expensive.
• “Simple” changes become risky because everything is interconnected.
• Integrations require custom workarounds.
• Infrastructure costs rise (backups, monitoring, patch cycles, legacy dependencies)

So even if you avoid a breach, you’re often paying more each year just to stay in place.

NAV vs. Business Central

Here’s the difference in plain terms: NAV can be secured, but it often requires heavier internal effort. Business Central (especially cloud) is designed so that security is easier to maintain continuously.

Your Migration Roadmap

Step 1: Start With a Security Risk Assessment

Before we talk migration tools and timelines, we need to understand your real exposure:

• What NAV version are you on (and your support deadline)
• Known vulnerabilities and patch status
• Authentication model (MFA? shared accounts?)
• Encryption and backup posture
• Third-party integrations and custom code risks
• Compliance requirements (GDPR, SOC2, industry-specific)

Step 2: Clean Up Data Before You Move It

The fastest migrations aren’t the ones that move everything. They’re the ones who move the right things.

We typically help teams.

• Archive old transactional history properly
• Remove duplicates and orphaned records
• Validate masters (items, vendors, and customers)
• Fix data issues that cause reporting pain later

Step 3: Go Live With “Quick Wins” People Actually Feel

A good Business Central go-live should immediately reduce risk and friction, like the following:

• MFA and modern access policies
• Mobile approvals and workflows
• Power BI reporting that isn’t a weekly struggle
• Automated backups and smoother patching
• Better visibility for finance and operations

Conclusion

If you’re still on NAV, you don’t need to panic; you need a plan.

At 2HatsLogic, we’ve been helping businesses modernize ERP and automation since 2009. We’ll start with a free NAV security assessment, show you where the real risks are, and map a practical path to Business Central that fits your timeline and budget.