# CVE-2026-87711: Microsoft Windows Installer stack buffer overflow privilege escalation

Source: https://junglewise.ai/threats/cve-2026-87711-stack-based-buffer-overflow-in-windows-installer-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-87711 · Severity: high · CVSS 7.8 · Published 2026-10-13

Windows Installer, a core component responsible for installing and managing software on Windows systems, contains a stack-based buffer overflow vulnerability. An attacker with local system access could exploit this flaw to gain elevated privileges and take full control of the affected computer.

Technologies: [Microsoft Windows Installer](https://junglewise.ai/threats/technologies/windows-installer), [Microsoft Windows 10 1607](https://junglewise.ai/threats/technologies/windows-10-1607), [Microsoft Windows 10 1809](https://junglewise.ai/threats/technologies/windows-10-1809), [Microsoft Windows 10 21h2](https://junglewise.ai/threats/technologies/windows-10-21h2), [Microsoft Windows 10 22h2](https://junglewise.ai/threats/technologies/windows-10-22h2), [Microsoft Windows 11 23h2](https://junglewise.ai/threats/technologies/windows-11-23h2), [Microsoft Windows 11 24h2](https://junglewise.ai/threats/technologies/windows-11-24h2), [Microsoft Windows 11 25h2](https://junglewise.ai/threats/technologies/windows-11-25h2), [Microsoft Windows 11 26h1](https://junglewise.ai/threats/technologies/windows-11-26h1), [Microsoft Windows 11 26h2](https://junglewise.ai/threats/technologies/windows-11-26h2), [Microsoft Windows Server 2012](https://junglewise.ai/threats/technologies/windows-server-2012), [Microsoft Windows Server 2016](https://junglewise.ai/threats/technologies/windows-server-2016), [Microsoft Windows Server 2019](https://junglewise.ai/threats/technologies/windows-server-2019), [Microsoft Windows Server 2022](https://junglewise.ai/threats/technologies/windows-server-2022), [Microsoft Windows Server 2025](https://junglewise.ai/threats/technologies/windows-server-2025). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-87711 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-87711 being exploited in the wild.

**How severe is CVE-2026-87711?** 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-2026-87711?** 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-2026-87711 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-87711?** 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 stack-based buffer overflow exists in Windows Installer that can be triggered by an authorized local attacker. The vulnerability allows an attacker with existing system access to overflow a stack buffer and execute arbitrary code with elevated privileges, resulting in complete system compromise.

## Affected products

- Microsoft Windows Installer

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87711](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87711)

## 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)