CVE-2026-97381 Legacy Update ActiveX control accepts unauthorized hosting origins
Attackers can bypass origin checks in the ActiveX control to read system info, install updates, or restart the computer via malicious webpages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-97381?
CVE-2026-97381 is a critical vulnerability in LegacyUpdate, published on 13 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Legacy Update is a tool for activating and installing updates on legacy Windows PCs. Legacy Update 1.12.0 through 1.13.1 contains an origin validation error in the IsPermitted method of its ActiveX control. After successfully reading the hosting document's hostname, a hostname that is not on the permitted list falls through without setting E_ACCESSDENIED, causing IsPermitted to return S_OK. An attacker who induces a user to visit a malicious webpage in Internet Explorer can invoke the control to enumerate update and system information, install updates without consent, display dialogs, or restart the computer when a reboot is pending. This issue was fixed in Legacy Update 1.13.2.
Which versions are affected by CVE-2026-97381?
How do I fix CVE-2026-97381?
No fix has been published for CVE-2026-97381 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-97381 being exploited?
There is no known exploitation of CVE-2026-97381 in the wild and no public exploit code.
Sources
Also known as GHSA-f4g7-4gmx-jfgf.