CVE-2026-58637: Microsoft Windows Client-Side Caching Service privilege escalation

CVE-2026-58637 · Severity: high · CVSS 7 · Published 2026-07-14

A security vulnerability exists in the Windows Client-Side Caching (CSC) Service, which manages offline access to network files. 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 2012. Vendors: Microsoft.

Quick answers

Is CVE-2026-58637 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-58637 being exploited in the wild.
How severe is CVE-2026-58637?
High severity, with a CVSS score of 7, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 11 24H2, 25H2, 26H1; Microsoft Windows 10 1607, 1809, 21H2, 22H2; Microsoft Windows Server 2012 All editions.
Is there a fix for CVE-2026-58637?
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-2026-58637 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-58637?
Check whether you run Microsoft Windows 11, Microsoft Windows 10 or Microsoft Windows Server 2012 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

A use-after-free (CWE-416) vulnerability exists within the Windows Client-Side Caching (CSC) Service. The flaw is triggered when the service incorrectly manages memory objects during file caching operations, allowing an attacker to reuse a memory pointer after it has been freed. To exploit this, an attacker must have local access to the target system and execute a specially crafted application. Successful exploitation enables the attacker to gain SYSTEM privileges. Microsoft has released security updates to address this issue across affected Windows and Windows Server versions.

Affected products

  • Microsoft Windows 10 1607, 1809, 21H2, 22H2
  • Microsoft Windows 11 24H2, 25H2, 26H1
  • Microsoft Windows Server 2012 All editions

Timeline

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

References

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