EUVD Vulnerability Catalog

EUVD-2026-100662

Severity: CRITICAL Base Score: 9.9 CVSS Version: 3.1

Vulnerability 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.

CVSS Vector Analysis

Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

▪ Attack Vector (AV): Network
▪ Attack Complexity (AC): Low
▪ Privileges Required (PR): Low
▪ User Interaction (UI): None
▪ Scope (S): Changed
▪ Confidentiality Impact (C): High
▪ Integrity Impact (I): High
▪ Availability Impact (A): High

Affected Vendors & Systems

Vendor LegacyUpdate

References & Advisory Links

Metadata Profile

Database Authority

European Union Agency for Cybersecurity (ENISA) EUVD

Assigner

GitHub_M

EPSS Probability

0.21

Known Aliases
CVE-2026-97381
Published On

2026-10-13

Last Updated

2026-10-17