PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-44809 Microsoft CVE debrief

CVE-2026-44809 is a HIGH severity vulnerability in the Windows Common Log File System Driver. The vulnerability is caused by a use-after-free issue, which allows an authorized attacker to elevate privileges locally. The CVSS score for this vulnerability is 7.8.

Vendor
Microsoft
Product
Windows 11 Version 24H2
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-11
Advisory published
2026-06-09
Advisory updated
2026-06-11

Who should care

Administrators and users of Microsoft Windows 11 and Windows Server 2025 systems should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability is caused by a use-after-free issue in the Windows Common Log File System Driver. This issue allows an authorized attacker to elevate privileges locally. The vulnerability affects multiple versions of Microsoft Windows 11 and Windows Server 2025.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates provided by Microsoft to vulnerable systems.
  • Ensure that all systems are up-to-date with the latest security patches.

Evidence notes

The vulnerability is documented in the CVE-2026-44809 CVE record [cve-org] and the NVD detail page [nvd]. Microsoft has also provided a vendor advisory for this vulnerability [ref-4].

Sources and references

Verified primary and authoritative sources

  • CVE-2026-44809 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-44809

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-44809 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44809

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.