Public vs. Private Vendor Risk Signals – Which Can You Trust?

TL;DR

How to Read Vendor Risk Signals Without Getting Burned

In 2025, risk teams face a paradox: more data, less clarity. Public signals (like security ratings and breach data) are objective but often superficial. Private disclosures (SOC 2s, questionnaires) offer more depth, but they’re self-reported and static. Neither tells the whole story – especially when products, partners, and threats evolve faster than annual reviews. The best third-party risk strategies blend both: using external signals to monitor shifts and internal artifacts to verify what matters. But the real differentiator isn’t how much data you collect – it’s how often and how clearly you interpret it.

Introduction: Why the Data You Trust Might Be Lying to You

Most third-party risk programs are built on trust signals that feel reliable – clean audit reports, green security ratings, filled-out questionnaires. But dig deeper, and those signals start to wobble.

A vendor might check every box and still leave your organization exposed. Not because they lied – because the signals you relied on didn’t tell the full story.

In 2025, risk leaders face a data saturation problem. There’s more vendor risk information than ever before. But quality hasn’t kept pace with quantity.

So how do you decide what to trust? And more importantly – what not to?

1. Public Risk Signals Are Continuous – but Often Superficial

Public risk signals include security ratings from platforms, threat intelligence from OSINT sources, and data about known breaches or leaked credentials. These tools provide an outside-in view of a vendor’s security posture, and their popularity is growing – especially for continuous monitoring.

That makes sense: these metrics are always-on, easy to benchmark, and don’t require vendor cooperation. If a vendor’s score drops, you get alerted. If their site is exposed or credentials leak, you can take action.

But here’s the catch: public data tends to focus on what’s easily observable. That means factors like expired SSL certificates, open ports on marketing infrastructure, or insecure email configurations.

What it often misses:

• Backend infrastructure tied to the actual product
• Application-layer vulnerabilities or insecure business logic
• Third-party sub-vendors that aren’t internet-exposed

That’s why many CISOs treat public ratings as a starting point, not a risk verdict. The data is real – but it’s also partial. It helps you scan for problems, not understand them.

2. Private Risk Signals Offer Depth – But Require Trust

Private signals are the vendor documents and attestations you gather during due diligence: SOC 2 reports, ISO certifications, pen test summaries, and completed security questionnaires.

These are useful because they speak directly to how the vendor runs security internally:

• How they manage access and authentication
• How often they patch systems
• How they train employees
• How incidents are reported and escalated

This kind of detail is what helps risk teams assess not just what a vendor’s posture is – but why it exists.

But there’s a catch here too: these documents are usually provided by the vendor themselves. They’re often out of date. And the accuracy of the data depends on the honesty and depth of the person filling it out.

Questionnaires especially are a weak link. In some cases, answers are filled out by someone without deep security knowledge – or with a vested interest in keeping things positive. An ISACA report even noted that many questionnaires fail basic validation checks.

So while private signals are rich in theory, they still require manual verification or supplemental proof. And most of them represent a moment in time – not a living picture of how the vendor’s controls behave today.

3. Risk Evolves Faster Than Either Signal Can Track

Whether it’s public or private, most vendor signals are inherently backward-looking. A SOC 2 report reflects what controls looked like over a previous 6–12 month period. A public risk rating reflects current surface hygiene – but doesn’t capture architectural changes behind the scenes.

In the real world:

• Vendors ship new features weekly
• AI tooling is being rapidly integrated
• New sub-vendors and service dependencies get added constantly

By the time your team reads a vendor’s SOC 2, their stack may already be different. And a security rating might show “good hygiene” while the vendor just integrated a risky third-party analytics tool.

Modern risk requires real-time understanding. Without dynamic data and continuous context, your program is reacting to shadows of the past.

4. Most Risk Lives in the Gaps Between Signals

What’s more dangerous than a bad signal? A misleadingly clean one.

Let’s say a vendor has a spotless SOC 2, a top-tier security rating, and a green-light questionnaire. Great, right?

Maybe. But maybe not.

• Did the SOC 2 exclude third-party infrastructure via carve-out?
• Did the rating platform dock them for a forgotten dev domain, but miss the app where PII lives?
• Did the questionnaire include vague answers like “N/A” or “proprietary information” for key controls?

The real risk isn’t usually found inside the signals. It’s found in the spaces between them – where no single view tells the full truth.

That’s why high-performing risk teams don’t just collect artifacts. They correlate them. They look for inconsistencies. They read between the lines.

5. Leading Teams Blend Signals, But Rely on Interpretation

There’s now widespread agreement in the TPRM world: relying on a single type of signal is risky. But more signals alone aren’t enough. You need better interpretation.

Mature teams combine public and private data, but they don’t stop there:

• They triage vendors based on real exposure – not just scorecards
• They validate private disclosures with external signals and AI-driven document analysis
• They trigger follow-up instant assessments when signals conflict or feel too perfect

Importantly, they recognize that collecting data isn’t the job. Understanding risk is.

Conclusion: In TPRM, More Data Isn’t the Answer – Better Insight Is

Public vendor signals give you scale. Private ones give you detail. But neither, on their own, give you truth.

In 2025, the vendors you work with are changing constantly – and so are their risks. To keep up, your risk visibility needs to move from static reviews to live insight.

That doesn’t mean giving up SOC 2s or security ratings. It means looking at them with the right lens:

• Are these signals aligned?
• Do they reflect current conditions?
• Can we verify what we’re being told?

And most importantly: what isn’t this telling us?

Because the cost of trusting a clean signal without verification isn’t just compliance failure. It’s operational failure. Customer trust lost. Headlines made.

And all because we thought a perfect score meant a perfect partner.