CVE-2026-85796: Windows Installer numeric truncation privilege escalation

CVE-2026-85796 · Severity: high · CVSS 7.8 · Published 2026-10-13

Windows Installer, the system component that installs and updates software on Windows machines, contains a numeric truncation error that allows an authorized user to elevate privileges to system level. This gives an attacker higher access to the affected computer, enabling them to modify system settings, install malware, or access sensitive data they otherwise couldn't reach.

Technologies: Microsoft Windows Installer, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2025. Vendors: Microsoft.

Quick answers

Is CVE-2026-85796 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-85796 being exploited in the wild.
How severe is CVE-2026-85796?
High severity, with a CVSS score of 7.8, published 13 October 2026.
Which products and versions are affected?
Microsoft Windows Installer.
Is there a fix for CVE-2026-85796?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-85796 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-85796?
Check whether you run Microsoft Windows Installer, Microsoft Windows 10 1607, Microsoft Windows 10 1809 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A numeric truncation error in Windows Installer permits local privilege escalation when exploited by an authenticated user. The vulnerability requires local access and prior authentication, but allows an attacker to gain elevated system privileges through improper integer handling in the installer component.

Affected products

  • Microsoft Windows Installer

Timeline

  • 2026-10-13: disclosed

References

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