SB2026071580 - Multiple vulnerabilities in Microsoft Windows App Package Installer

Description

This security bulletin contains information about 3 vulnerabilities.

1) Race condition (CVE-ID: CVE-2026-48572)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition in Windows App Package Installer. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

2) Stack-based buffer overflow (CVE-ID: CVE-2026-50400)

CWE-ID: CWE-121 - Stack-based buffer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to a boundary error in Windows App Package Installer. A local user can trigger stack-based buffer overflow and gain elevated privileges on the system.

3) Use-after-free (CVE-ID: CVE-2026-48571)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Windows App Package Installer. A local user can win a race condition and gain elevated privileges on the system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-48572
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50400
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-48571