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

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, 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-2026-87711 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

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