CVE-2026-58536: Microsoft Windows Cloud Files Mini Filter Driver use after free

CVE-2026-58536 · Severity: high · CVSS 7.8 · Published 2026-07-14

A security vulnerability exists in the Windows component responsible for managing cloud-based files, such as those used by OneDrive. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative control over the system. This could allow them to view sensitive data, install malicious software, or disrupt business operations.

Technologies: Microsoft Windows 11, Microsoft Windows 10, Microsoft Windows Server 2019, Microsoft Windows Server 2022. Vendors: Microsoft.

Quick answers

Is CVE-2026-58536 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-58536 being exploited in the wild.
How severe is CVE-2026-58536?
High severity, with a CVSS score of 7.8, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 11 24H2, 25H2, 26H1; Microsoft Windows 10 1809, 21H2, 22H2; Microsoft Windows Server 2019 All versions; Microsoft Windows Server 2022 All versions.
Is there a fix for CVE-2026-58536?
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-2026-58536 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-58536?
Check whether you run Microsoft Windows 11, Microsoft Windows 10, Microsoft Windows Server 2019 or one of the others listed at an affected version. 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

This vulnerability is classified as a use-after-free (CWE-416) within the Windows Cloud Files Mini Filter Driver (cldflt.sys). The flaw is triggered when the driver incorrectly manages memory objects during file operations, allowing an attacker to execute code in kernel mode. To exploit this, an attacker must first have local access to the target system with low-level user privileges. Successful exploitation results in a complete local privilege escalation (LPE), granting the attacker SYSTEM-level access. Microsoft has released security updates to address this issue across affected versions of Windows 10, Windows 11, and Windows Server.

Affected products

  • Microsoft Windows 10 1809, 21H2, 22H2
  • Microsoft Windows 11 24H2, 25H2, 26H1
  • Microsoft Windows Server 2019 All versions
  • Microsoft Windows Server 2022 All versions

Timeline

  • 2026-07-14: disclosed
  • 2026-07-14: advisory

References

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