Why XAV Matters: Blind Spots Your RMM or MDM Can’t See

Most IT and security teams trust their RMM or MDM to tell them what’s installed across their fleet. You pull up the console and run a report, and see every required agent listed. XDR, DNS filter, remote control, SIEM agent, the works. From that view it looks like every machine is covered.

But the problem is, those tools can only report what they can see.
Your RMM knows that an agent’s executable exists on disk, but it doesn’t know if it’s actually running, healthy, or checking in. Your MDM can confirm a configuration profile was deployed, but not whether the service behind it is silently broken.

Sooner or later, you stumble across a machine that “has” all the right agents but isn’t actually protected — and you realize your single pane of glass has blind spots of its own.

What this looks like in practice

These blind spots aren’t hypothetical, they show up in the most ordinary ways:

• A device still has its XDR agent installed, so it shows up green in your report on your RMM/MDM. But the XDR agent is missing a key configuration file after a bad patch cycle! The XDR service is online — but it's unprotected and missing your security policies. It’s in a limbo state, yet your RMM/MDM tool told you it was healthy.
• An endpoint’s SIEM agent is technically present, but a restrictive firewall policy blocks its outbound traffic to the management console. Locally it looks “healthy,” but in the console it’s completely dark. But your RMM/MDM tool told you it was installed and healthy.
• A laptop is imaged from an old template. The MDM thinks it’s compliant, the antivirus agent reports an ancient version, and no one notices because all the tools trust each other’s data.

None of these cases would trigger a clean alert. They all look fine from a standard monitoring implementation on an RMM or MDM.

In most environments, the only way these edge cases get caught is through manual exports from each agent platform — CSVs, and spreadsheet comparisons that someone has to babysit.
Some teams go further and build custom monitors or scripts to check for specific conditions — an agent missing a file here, a service not reporting there. But that approach is time-consuming, brittle, and adds its own maintenance overhead.

And even with all that work, new edge cases keep showing up. Additionally, the RMM or MDM that you built all your custom monitors on has its own potential blind spots and weaknesses.

There has to be a better way to catch these before they slip through the cracks, right?

Cross-Agent Verification (XAV) closes the gaps

Cross-Agent Verification, or XAV, is a way to double-check what your tools claim. Instead of trusting a single platform’s word, XAV cross-references data from all of them — RMM, XDR, MDM, DNS, patching, and beyond — to build a single, verified view of what’s really installed and reporting.

It doesn’t replace your existing tools. It validates them.

Where an RMM says “this device is online,” XAV checks whether the XDR or SIEM agrees.
Where a tool claims “agent healthy,” XAV looks at update cadence, last check-in, and peer data to confirm it’s true.

That correlation turns scattered telemetry into something solid — a trustworthy source of truth across your entire fleet.

Why we built Fieldmark XAV

We built Fieldmark XAV because we were tired of chasing ghosts in spreadsheets.

Every IT and security team we talked to had the same story: half their day was spent reconciling what one tool said versus another. RMM says 2,000 devices. XDR says 1,935. Which number is right?

Fieldmark XAV automates that verification. It connects to the tools you already use, pulls their device data, and continuously compares it — flagging gaps where something’s missing, stale, or out of sync. No more manual exports, no more guesswork.

When one of your agents goes dark, Fieldmark XAV tells you before it becomes a problem.

Bottom line: your RMM and XDR see their own corners of the world. Fieldmark XAV’s Cross-Agent Verification connects those dots — so you finally know, with confidence, what’s actually deployed and what isn’t.

Robert Katic - Founder, Fieldmark.io