Vulnerability · Published Oct 13, 2026 · Assigned by GitHub_M
CVE-2026-97381Legacy Update ActiveX control accepts unauthorized hosting origins
Critical 9.9
In plain English
A critical-severity security flaw in LegacyUpdate from LegacyUpdate. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| LegacyUpdate | LegacyUpdate | >= 1.12.0, < 1.13.2 |
Weakness: CWE-346, CWE-393 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/LegacyUpdate/LegacyUpdate/security/advisories/GHSA-f4g7-4gmx-jfgf x_refsource_CONFIRM
- https://github.com/LegacyUpdate/LegacyUpdate/commit/7d62f0bfaa770d74cd6e2cb0bac9c1907df48033 x_refsource_MISC
- https://github.com/LegacyUpdate/LegacyUpdate/commit/ae1c46c97f39a55a1937784d9f9beb30aa9147fd x_refsource_MISC
- https://github.com/LegacyUpdate/LegacyUpdate/releases/tag/v1.13.2.0 x_refsource_MISC
- https://legacyupdate.net/news/2026/07/21/legacy-update-1-13-2 x_refsource_MISC