SB2026071513 - Multiple vulnerabilities in Microsoft Windows Overlay Filter

Description

This security bulletin contains information about 3 vulnerabilities.

1) Heap-based buffer overflow (CVE-ID: CVE-2026-54987)

CWE-ID: CWE-122 - Heap-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 Overlay Filter. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the system.

2) Information disclosure (CVE-ID: CVE-2026-50409)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

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

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in Windows Overlay Filter. A local user can gain unauthorized access to sensitive information on the system.

3) Out-of-bounds read (CVE-ID: CVE-2026-50435)

CWE-ID: CWE-125 - Out-of-bounds read

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 gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in Windows Overlay Filter. A local user can trigger an out-of-bounds read error and read contents of memory on the system, leading to privilege escalation.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54987
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50409
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50435