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PatchSiren cyber security CVE debrief

CVE-2026-26153 Microsoft CVE debrief

A Windows Encrypted File System (EFS) Elevation of Privilege Vulnerability exists due to an out-of-bounds read in Windows Encrypting File System (EFS). An authorized attacker can elevate privileges locally. This vulnerability impacts Windows systems, particularly those with sensitive data or high-privilege access. Defenders should assess exposure and prioritize patching. The vulnerability allows local privilege escalation, making it crucial to verify system configurations and inventory for affected versions.

Vendor
Microsoft
Product
Windows 10 Version 1809
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-14
Original CVE updated
2026-10-15
Advisory published
2026-04-14
Advisory updated
2026-10-15

Who should care

Defenders responsible for Windows systems, especially those with sensitive data or high-privilege access, should assess exposure and prioritize patching.

Why it matters

CVE-2026-26153 allows local privilege escalation in Windows Encrypted File System (EFS). Defenders should prioritize patching and monitoring.

  • Local privilege escalation is possible for authorized attackers.
  • Patching affected versions is crucial to prevent exploitation.
  • System configurations and inventory should be verified for affected versions.
  • Monitoring for potential local privilege escalation attempts is recommended.

Technical summary

The vulnerability exists in the Windows Encrypting File System (EFS) due to an out-of-bounds read. An authorized attacker can exploit this to elevate privileges locally. The vulnerability impacts Windows 10, Windows 11, and Windows Server versions. Defenders should prioritize patching affected versions and verify system configurations and inventory. Monitoring for potential local privilege escalation attempts is recommended.

Defensive priority

Defenders should prioritize patching affected Windows versions, especially for systems with sensitive data or high-privilege access.

Recommended defensive actions

  • Patch affected Windows 10, Windows 11, and Windows Server versions.
  • Verify system configurations and inventory for affected versions.
  • Monitor for potential local privilege escalation attempts.

Evidence notes

The CVE Program and NVD provide official records of the vulnerability. Microsoft provides a vendor advisory with patch information. Evidence is limited to publicly available sources, and defenders should verify affected scope and vendor guidance. The vulnerability is confirmed in Windows Encrypting File System (EFS), but specific details about affected versions and configurations are limited.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-26153 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-26153

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

  • CVE-2026-26153 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-26153

    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.