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CVE-2026-62688: Windows MIDI Service Module Elevation of Privileges Vulnerability

CVE-2026-62688 is an elevation of privilege vulnerability in Windows MIDI Service Module Elevation of Privileges, rated Important by Microsoft, with a CVSS 3.1 base score of 7.8 (High). An attacker can exploit it by an attacker with local access, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as more likely. The EPSS model estimates a 0.33% probability of exploitation activity in the next 30 days, higher than 27% of all scored vulnerabilities. Microsoft released the fix on 11 August 2026 in the August 2026 Patch Tuesday, delivered through 3 security updates (KB5121003, KB5120994, KB5121000). It affects 6 products in 1 product family (Windows).

Key facts

CVE ID
CVE-2026-62688
Severity
High CVSS 7.8
Microsoft severity
Important
Impact
Elevation of Privilege
Exploited in the wild
No
Publicly disclosed
No
Exploitation likelihood
More Likely
Weakness
CWE-122
EPSS
0.33% (percentile 27%)
CISA KEV
Not listed
Released
Last updated
Patch Tuesday
August 2026 Patch Tuesday
Product families
Windows

CVSS score and vector

Microsoft scores CVE-2026-62688 at 7.8 (temporal 6.8) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

MetricValue
Attack vectorLocal
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit code maturityUnproven
Remediation levelOfficial fix
Report confidenceConfirmed

Description

Heap-based buffer overflow in Windows MIDI Service Module allows an authorized attacker to elevate privileges locally.

Frequently asked questions (Microsoft)

What privileges could be gained by an attacker who successfully exploited this vulnerability?

An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

Affected products (6)

Windows

ProductSecurity updateTypeFixed buildRestart
Windows 11 Version 25H2 for ARM64-based SystemsKB5121003
KB5120994		Security Update
Security Hotpatch Update		10.0.26200.9168
10.0.26200.9106		Yes
Yes
Windows 11 Version 25H2 for x64-based SystemsKB5121003
KB5120994		Security Update
Security Hotpatch Update		10.0.26200.9168
10.0.26200.9106		Yes
Yes
Windows 11 Version 24H2 for ARM64-based Systems
Windows 11 Version 24H2 for x64-based Systems
Windows 11 version 26H1 for x64-based SystemsKB5121000Security Update10.0.28000.2704Yes
Windows 11 Version 26H1 for ARM64-based SystemsKB5121000Security Update10.0.28000.2704Yes

Security updates (3)

NIST NVD data

NVD status
Analyzed
NVD CVSS
7.8 (HIGH)
NVD weakness
CWE-122
Published to NVD
NVD last modified

Affected configurations (CPE)

ProductVulnerable versions
windows 11 24h2 (arm64)before 10.0.26100.9106
windows 11 24h2 (x64)before 10.0.26100.9106
windows 11 25h2 (arm64)before 10.0.26200.9106
windows 11 25h2 (x64)before 10.0.26200.9106
windows 11 26h1 (arm64)before 10.0.28000.2704
windows 11 26h1 (x64)before 10.0.28000.2704

References

Acknowledgments

Revision history

VersionDateDescription
1.0Information published.
1.1Acknowledgement Updated
1.2Updated an acknowledgement. This is an informational change only.
1.3Updated an acknowledgement. This is an informational change only.
1.4Updated an acknowledgement. This is an informational change only.
1.5Updated an acknowledgement. This is an informational change only.

Sources