Legacy Update ActiveX control lets unauthorized websites invoke it
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-346.
Summary
Legacy Update from 1.12.0 before 1.13.2 is affected. An origin validation error (CWE-346) in the IsPermitted method of its ActiveX control lets requests from hostnames that are not on the permitted list succeed, because the method returns success instead of denying access. A remote attacker who lures a user to a malicious webpage in Internet Explorer can enumerate update and system information, install updates without consent, display dialogs, or restart the computer when a reboot is pending.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| LegacyUpdate | LegacyUpdate | 1.12.0 to before 1.13.2 | 1.13.2 | Patch available | CNA |
- LegacyUpdate VendorLegacyUpdate Affected 1.12.0 to before 1.13.2 Fixed in 1.13.2 Patch available CNA
Remediation
Update Legacy Update to version 1.13.2, which fixes this issue.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA LegacyUpdate (LegacyUpdate) Fixed in 1.13.2
Timeline
- 2026-10-13 Threatist record created from CVE-2026-97381
- 2026-10-18 CISA SSVC decision points changed
References
Other 5
- https://github.com/LegacyUpdate/LegacyUpdate/security/advisories/GHSA-f4g7-4gmx-jfgf
- https://github.com/LegacyUpdate/LegacyUpdate/commit/7d62f0bfaa770d74cd6e2cb0bac9c1907df48033
- https://github.com/LegacyUpdate/LegacyUpdate/commit/ae1c46c97f39a55a1937784d9f9beb30aa9147fd
- https://github.com/LegacyUpdate/LegacyUpdate/releases/tag/v1.13.2.0
- https://legacyupdate.net/news/2026/07/21/legacy-update-1-13-2
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences