CVE-2026-85358: Microsoft Windows Installer heap-based buffer overflow

CVE-2026-85358 · Severity: high · CVSS 7.8 · Published 2026-10-13

Windows Installer, a system component that installs and manages software on Windows computers, contains a heap buffer overflow vulnerability. An authorized user with local access can exploit this flaw to run arbitrary code with elevated system privileges, potentially compromising the entire computer.

Technologies: Microsoft Windows Installer. Vendors: Microsoft.

Quick answers

Is CVE-2026-85358 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-85358 being exploited in the wild.
How severe is CVE-2026-85358?
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-2026-85358?
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-2026-85358 attacked?
It is attacked with local access.
Am I affected by CVE-2026-85358?
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

A heap-based buffer overflow exists in Windows Installer that can be triggered by an authenticated local attacker. The vulnerability allows memory corruption leading to privilege escalation from a standard user to system-level access. Exploitation requires local access and prior authentication on the target system.

Affected products

  • Microsoft Windows Installer

Timeline

  • 2026-10-13: disclosed

References

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