Free practical cybersecurity guidance for organisations without a security team.
hello@actionsoncyber.com
Actions On Cyber logo
Contact
← Back to Vulnerability Briefs

Important Windows Security Update Needed to Stop Local Hackers Gaining Control

A serious security weakness has been found in Microsoft Windows that could let someone with access to your computer gain higher control than they should have. This vulnerability is already being actively exploited, so it is important to act quickly to protect your systems.

09 September 2026

Reference: CVE-2026-81963

1. What is being reported?

Microsoft has identified a flaw in how Windows handles certain file links during updates. This flaw can allow someone who already has some access to your computer to increase their privileges, potentially taking over the system or accessing sensitive information.

2. What this means in plain English

If an attacker can get onto your computer, even with limited access, they might use this flaw to gain full control. This could lead to data theft, disruption of your services, or other harmful actions. Small organisations using Windows should be aware that this is a high-risk issue.

3. Could this affect a small business?

Any small business, charity, club, or organisation using Microsoft Windows could be affected, especially if their computers are connected to the internet or shared networks. Those not using Windows or who have strict access controls may be less at risk, but it is best to check with your IT support.

4. What to do now

  • Contact your IT provider or software supplier immediately to ensure the latest Windows security updates are applied.
  • Verify that your systems comply with recommended security update policies, especially those prioritised by government guidance.
  • Review who has access to your computers and limit privileges to only those necessary.
  • If you use cloud services or third-party providers, confirm they have applied relevant patches or mitigations.

5. Ask your IT provider

Have you applied the latest security updates from Microsoft addressing the Windows link following vulnerability CVE-2026-81963, and can you confirm our systems are protected against this known exploited issue?

6. Bottom line

Apply Windows security updates promptly to prevent attackers from gaining full control of your computers.

Information based on CISA KEV, NVD, and reputable security reports.

Back to Vulnerability Briefs