# CVE-2026-119903: Windows Installer improper access control privilege escalation

Source: https://junglewise.ai/threats/cve-2026-119903-improper-access-control-in-windows-installer-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-119903 · Severity: high · CVSS 7.8 · Published 2026-11-10

Windows Installer, the system component that manages software installation on Windows, contains an access control vulnerability that allows an authenticated attacker to elevate their privileges to a higher level of system access. An attacker with local access to a Windows machine could exploit this flaw to gain administrative control, enabling them to install malware, steal data, or compromise system integrity.

Technologies: [Microsoft Windows Installer](https://junglewise.ai/threats/technologies/windows-installer). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-119903 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-119903 being exploited in the wild.

**How severe is CVE-2026-119903?** High severity, with a CVSS score of 7.8, published 10 November 2026.

**Which products and versions are affected?** Microsoft Windows Installer.

**Is there a fix for CVE-2026-119903?** 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-2026-119903 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-119903?** Check whether you run Microsoft Windows Installer. 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

The vulnerability is an improper access control issue in Windows Installer that permits privilege escalation via local attack vector. An authorized attacker with user-level access can exploit this vulnerability to gain elevated (administrative) privileges on the system without requiring additional authentication or user interaction.

## Affected products

- Microsoft Windows Installer

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119903](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119903)

## Related threats

- [Microsoft Windows Installer stack-based buffer overflow](https://junglewise.ai/threats/cve-2026-96152-stack-based-buffer-overflow-in-windows-installer-allows-an)
- [Windows Installer heap-based buffer overflow allows privilege elevation](https://junglewise.ai/threats/cve-2026-96085-heap-based-buffer-overflow-in-windows-installer-allows-an)
- [Microsoft Windows Installer heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-96062-heap-based-buffer-overflow-in-windows-installer-allows-an)
- [Windows Installer use-after-free privilege elevation](https://junglewise.ai/threats/cve-2026-96061-use-after-free-in-windows-installer-allows-an-authorized-attacker)
- [Windows Installer out-of-bounds read privilege escalation](https://junglewise.ai/threats/cve-2026-96060-out-of-bounds-read-in-windows-installer-allows-an-authorized)