SB2026011380 - Multiple vulnerabilities in Microsoft Windows Virtualization-Based Security (VBS)

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Untrusted Pointer Dereference (CVE-ID: CVE-2026-20819)

The vulnerability allows a local user to gain access to sensitive information on the system.

The vulnerability exists due to untrusted pointer dereference in Windows Virtualization-Based Security (VBS). A local user can disclose sensitive information on the target system.

2) Untrusted Pointer Dereference (CVE-ID: CVE-2026-20935)

The vulnerability allows a local attacker to gain access to sensitive information on the system.

The vulnerability exists due to untrusted pointer dereference in Windows Virtualization-Based Security (VBS). A local attacker can disclose sensitive information on the target system.

3) Untrusted Pointer Dereference (CVE-ID: CVE-2026-20938)

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

The vulnerability exists due to untrusted pointer dereference in Windows Virtualization-Based Security (VBS). A local user can gain elevated privileges on the target system.

4) Heap-based buffer overflow (CVE-ID: CVE-2026-20876)

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

The vulnerability exists due to a boundary error in Windows Virtualization-Based Security (VBS) Enclave. A local administrator can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the target system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20819
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20935
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20938
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876