Vulnerability · Published Jun 9, 2026 · Assigned by microsoft
CVE-2026-42915Microsoft Windows VMSwitch Denial of Service Vulnerability
Medium 5.5
In plain English
A medium-severity security flaw in Windows 10 Version 21H2 from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).
Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.4%top 67.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Incorrect calculation of buffer size in Windows VMSwitch allows an authorized attacker to deny service locally.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 Version 21H2 | 10.0.19044.0 – before 10.0.19044.7417 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 – before 10.0.19045.7417 |
| Microsoft | Windows 11 version 23H2 | 10.0.22631.0 – before 10.0.22631.7219 |
| Microsoft | Windows 11 Version 23H2 | 10.0.22631.0 – before 10.0.22631.7219 |
| Microsoft | Windows 11 Version 24H2 | 10.0.26100.0 – before 10.0.26100.8655 |
| Microsoft | Windows 11 Version 25H2 | 10.0.26200.0 – before 10.0.26200.8655 |
| Microsoft | Windows 11 version 26H1 | 10.0.28000.0 – before 10.0.28000.2269 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – before 10.0.20348.5256 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 – before 10.0.26100.32995 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 – before 10.0.26100.32995 |
Weakness: CWE-131 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
References
- Microsoft Windows VMSwitch Denial of Service Vulnerability vendor-advisory, patch