What is the CVSS score of EUVD-2026-56329?

EUVD-2026-56329 has a CVSS 3.1 base score of 5.5 (Medium). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N. EPSS exploitation probability: 0.5%.

Is there a patch available for EUVD-2026-56329?

Yes, a patch is available for EUVD-2026-56329. Update the affected software to the latest version immediately.

Windows Hyper-V EUVD-2026-56329

| CVE-2026-61368 MEDIUM

Heap-based Buffer Overflow (CWE-122)

2026-08-11 secure@microsoft.com

GHSA-gj7f-3gp2-7v6x

Buffer Overflow Heap Overflow Microsoft Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 23h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2025

5.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.5 MEDIUM

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

vuln.today AI

5.0 MEDIUM

Local vector and low privileges reflect an authorized local attacker; UI:R for required interaction; C:H for meaningful heap memory disclosure; I:N and A:N as no integrity or availability impact is described.

3.1 AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

4.0 AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

CVSS changed

Aug 13, 2026 - 15:52 NVD

5.0 (MEDIUM) 5.5 (MEDIUM)

Analysis Generated

Aug 11, 2026 - 23:11 vuln.today

Patch available

Aug 11, 2026 - 18:19 EUVD

CVE Published

Aug 11, 2026 - 17:18 nvd

MEDIUM 5.0

DescriptionNVD

Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to disclose information locally.

AnalysisAI

Windows Hyper-V across a broad range of Windows 10, Windows 11, and Windows Server releases contains a heap-based buffer overflow (CWE-122) that enables a locally authenticated low-privileged attacker to disclose confidential memory contents. The CVSS vector (AV:L/PR:L/UI:R/S:U/C:H/I:N/A:N) constrains the attack to local access with required user interaction and produces no integrity or availability impact. No public exploit has been identified and this vulnerability is not listed in the CISA KEV catalog at the time of analysis.

Technical ContextAI

Windows Hyper-V is Microsoft's Type-1 hypervisor integrated into Windows 10/11 Pro and Enterprise editions and all Windows Server SKUs from 2016 onward. CWE-122 (Heap-based Buffer Overflow) identifies the root cause as a write operation that exceeds the bounds of a heap-allocated buffer, potentially overwriting adjacent heap structures or data regions. In a hypervisor context, such overflows carry elevated risk because the heap may contain cross-VM or host-mapped memory mappings; a read-side disclosure from the corrupted region could expose guest or host confidential data to an unprivileged caller. Affected builds span from 10.0.14393 (Windows 10 1607 and Server 2016) through 10.0.28000 (Windows 11 26H1), covering every major Windows release over a decade of Hyper-V deployment.

RemediationAI

Apply the Microsoft security update for CVE-2026-61368 via Windows Update or the Microsoft Update Catalog. Patched build thresholds per platform are: Windows 10 1607 and Server 2016 - build 10.0.14393.9418 or later; Windows 10 1809 and Server 2019 - build 10.0.17763.9115 or later; Windows 10 21H2 - build 10.0.19044.7663 or later; Windows 10 22H2 - build 10.0.19045.7663 or later; Windows Server 2022 - build 10.0.20348.5499 or later; Windows 11 23H2 - build 10.0.22631.7517 or later; Windows 11 24H2 and Server 2025 - build 10.0.26100.9168 or later (desktop) / 10.0.26100.33296 or later (Server 2025); Windows 11 25H2 - build 10.0.26200.9168 or later; Windows 11 26H1 - build 10.0.28000.2704 or later. If patching cannot be applied immediately, disabling the Hyper-V Windows Feature on non-essential workstations eliminates the attack surface entirely, at the cost of losing all virtualization capability on those hosts. Enforcing least-privilege access policies - ensuring that no standard domain users hold local interactive logon rights on Hyper-V hosts - reduces the pool of potential attackers and is a sound compensating control. Full advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-61368.