Nearly Every Large Company Has a Breached Vendor

Conference research often highlights how interconnected modern businesses are. When most large companies share suppliers that have experienced a breach, the lesson is that third-party risk is a normal part of operating, not an unusual event.

Why vendors create risk

Suppliers often hold data or have access to your systems. If their security fails, attackers may reach you through trusted connections such as shared accounts, integrations or software updates.

Know your suppliers

Maintain a list of vendors, the data they hold and the access they have. You cannot manage risk you cannot see, and many organisations discover forgotten connections during this exercise.

Assess before and during the relationship

Ask for security documentation, check certifications and include security requirements in contracts. Reassess important vendors regularly, not only at signing.

Limit the blast radius

Give vendors only the access they need, use separate credentials, require multi-factor authentication and monitor their activity. Remove access promptly when a contract ends.

Prepare for incidents

Agree notification timelines in contracts and rehearse how you would respond if a key supplier were compromised.

Key takeaways

• Why vendors create risk: Suppliers often hold data or have access to your systems. If their security fails, attackers may reach you through trusted connections such as shared accounts, integrations or software updates.
• Know your suppliers: Maintain a list of vendors, the data they hold and the access they have. You cannot manage risk you cannot see, and many organisations discover forgotten connections during this exercise.
• Assess before and during the relationship: Ask for security documentation, check certifications and include security requirements in contracts. Reassess important vendors regularly, not only at signing.
• Limit the blast radius: Give vendors only the access they need, use separate credentials, require multi-factor authentication and monitor their activity. Remove access promptly when a contract ends.
• Prepare for incidents: Agree notification timelines in contracts and rehearse how you would respond if a key supplier were compromised.

Putting it into practice

To apply this in your own organization, begin with a short assessment of where you stand on third-party vendor breach risk today. Write down who owns it, which tools are involved, and the single biggest gap. Fix the highest-risk gap first, assign a clear date, and review progress after thirty days. Share what you learn with the team so improvements stick, and document the decisions you make so new staff can follow them. Revisit the topic every quarter, because threats, tools, and business needs change quickly, and small regular adjustments are far easier than large emergency fixes.

Common mistakes to avoid

Many teams struggle with third-party vendor breach risk because they try to do everything at once, skip documentation, or treat it as a one-time project. Others rely on a single person who holds all the knowledge, or buy tools before defining the problem they need to solve. Avoid these traps by starting small, writing down simple procedures, spreading responsibility across the team, and checking results on a regular schedule. If something is not working, adjust quickly instead of abandoning the effort, and keep a short log of what you changed and why. That record makes future decisions faster and helps new colleagues understand the reasoning behind your approach.

Frequently asked questions

Is every vendor high risk?

No. Focus on those with sensitive data or deep system access.

What is the first step?

Create an inventory of vendors and the access each one has.

Final thoughts

Third-party risk cannot be eliminated, but visibility, limited access and clear contracts keep it manageable.