09 September 2026
Reference: CVE-2026-85880
1. What is being reported?
The issue is a weakness in how Windows handles certain internal communications, called ALPC. This flaw can cause a buffer overflow, which means attackers who already have some access to a computer could use it to increase their control and potentially take over the system.
2. What this means in plain English
If an attacker can exploit this flaw, they might be able to do things they shouldn’t be able to, such as installing software, changing settings, or accessing sensitive information. For small organisations, this could lead to data breaches or disruption of services.
3. Could this affect a small business?
Any small business or charity using Microsoft Windows on their computers could be affected, especially if their systems are not fully updated. Those who use Windows but have strong controls limiting user access or use cloud services with managed security may be less at risk. However, it is best to check with your IT provider.
4. What to do now
- Contact your IT provider immediately to ensure all Windows systems are updated with the latest security patches.
- Verify that your organisation follows recommended security update practices as advised by official guidance.
- Review which devices have internet exposure and prioritise patching those first.
- If your organisation uses cloud services, confirm with your provider that appropriate mitigations are in place or consider discontinuing use if not.
5. Ask your IT provider
Can you confirm that all our Windows devices have been patched against the CVE-2026-85880 vulnerability and that we are following the latest security update guidance?
6. Bottom line
Make sure your Windows systems are fully updated now to prevent attackers from gaining control of your computers.
Information based on CISA KEV, NVD and reputable security reporting.