SB20260917240 - Double free in Microsoft Windows
Published: September 17, 2026
Security Bulletin ID
SB20260917240
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Double free (CVE-ID: CVE-2026-85921)
CWE-ID: CWE-415 - Double Free
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to elevate privileges.
The vulnerability exists due to a double free in Windows Secure Kernel Mode when exploiting the secure kernel locally. A local privileged user can trigger the double free to elevate privileges.
Successful exploitation can result in Virtual Trust Level 1 (VTL1) privileges.
Remediation
Install update from vendor's website.