“Privilege escalation” is one of those security terms that sounds deeply technical but describes something simple: an attacker getting more access than they’re meant to have. It’s in the headlines this week because Microsoft confirmed a privilege-escalation flaw in Microsoft Defender (CVE-2026-41091) is being actively exploited, as reported by The Hacker News. So it’s worth two minutes to understand what it actually means for your business.

Think of your office. Getting through the front door is one thing. Getting hold of a master key that opens every room, the safe and the server cupboard is another thing entirely. Privilege escalation is that second part. Attackers rarely land exactly where they want to be — they get a toehold first, maybe through a phished password or malware on a single laptop, with the limited rights of one ordinary user. A privilege-escalation bug is the master key: it bumps that everyday foothold up to “administrator” or SYSTEM — the account that can install anything, turn off security tools and reach other machines. That’s why these flaws are so prized. The break-in gets the headlines; the escalation is what turns it into a genuine incident.

For a business owner, the takeaway isn’t to memorise CVE numbers. It’s that two unglamorous habits do most of the work to blunt these attacks. First, patch promptly — most escalation bugs are fixed long before they’re widely abused. Second, don’t hand out administrator rights by default; everyday staff accounts should run as standard users, so a stolen login is worth far less. Decent endpoint protection helps too, by flagging the odd behaviour that escalation tends to create.

Not sure how many people in your business are running with full admin rights, or whether your patching is actually keeping up? Our cybersecurity team can take a look and give you a straight answer.