Actively exploited vulnerability
Microsoft Windows: improper access control flaw under attack
CVE-2025-59230 · Microsoft Windows Improper Access Control Vulnerability
What is affected
Microsoft Windows is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
Microsoft Windows contains an improper access control vulnerability in Windows Remote Access Connection Manager which could allow an authorized attacker to elevate privileges locally.
What an attacker can do
This is a improper access control flaw. It lets an attacker perform actions or reach data that should be restricted to authorised users.
- How it is reached
- Needs access to the device or a file opened on it
- Access the attacker needs
- A basic user account
- Does the victim have to do something?
- No, works without the victim doing anything
What to do
- Update Microsoft Windows now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor advisories and fixes
- msrc.microsoft.commsrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-59230
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on October 14, 2025, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by November 4, 2025, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 2.7% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 85% of all scored vulnerabilities.
Its CVSS severity score is 7.8 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
Improper access control in Windows Remote Access Connection Manager allows an authorized attacker to elevate privileges locally.