Junglewise Threat Intelligence

CVE-2026-50406: Microsoft Windows Backup Engine use after free privilege escalation

CVE-2026-50406 · Severity: high · CVSS 7 · Published 2026-07-14

Technologies: Microsoft Windows 10 Version 21H2, Microsoft Windows 11 Version 26H1, Microsoft Windows 11 Version 24H2, Microsoft Windows 10 Version 22H2, Microsoft Windows 10, Microsoft Windows 11, Microsoft Windows 11 Version 25H2. Vendors: Microsoft.

Executive brief

A security vulnerability has been identified in the Windows Backup Engine, a core component responsible for system and data recovery. 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 files, install malicious software, or disrupt business operations.

Technical details

A use-after-free vulnerability (CWE-416) exists in the Windows Backup Engine. The flaw is triggered when the engine incorrectly manages memory objects during backup operations, allowing a locally authenticated attacker with low privileges to execute code in a higher-privileged context. Exploitation requires the attacker to win a race condition or navigate complex timing (High Attack Complexity). Successful exploitation results in a complete loss of confidentiality, integrity, and availability as the attacker achieves SYSTEM-level privileges. Microsoft has released security updates to address this issue across affected Windows 10 and 11 versions.

Affected products

  • Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548
  • Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548
  • Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
  • Microsoft Windows 11 Version 25H2 10.0.26200.0 to 10.0.26200.8875
  • Microsoft Windows 11 version 26H1 10.0.28000.0 to 10.0.28000.2269

Timeline

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

References

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