CVE-2026-42915
Microsoft Windows VMSwitch Denial of Service Vulnerability
Incorrect calculation of buffer size in Windows VMSwitch allows an authorized attacker to deny service locally.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Windows VMSwitch Denial of Service Vulnerability
Incorrect calculation of buffer size in Windows VMSwitch allows an authorized attacker to deny service locally.
- Record
CVE-2026-42915- CVSS 3.1
- 5.5 Medium
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 - Weakness
- CWE-131
- Updated
- 2026-11-11
EUVDEUVD-2026-35727
Incorrect calculation of buffer size in Windows VMSwitch allows an authorized attacker to deny service locally.
- Record
EUVD-2026-35727- CVSS 3.1
- 5.5 Medium
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 - Updated
- 2026-11-11
GitHub AdvisoriesGHSA-3pg4-4j29-q4rr
Incorrect calculation of buffer size in Windows TCP/IP allows an authorized attacker to deny...
Incorrect calculation of buffer size in Windows TCP/IP allows an authorized attacker to deny service over an adjacent network.
- Record
GHSA-3pg4-4j29-q4rr- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-131
- Updated
- 2026-11-02
NVD
Incorrect calculation of buffer size in Windows VMSwitch allows an authorized attacker to deny service locally.
- Record
CVE-2026-42915- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-131
- Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 21h2
- microsoft windows 10 version 22h2
- microsoft windows 11 version 23h2
- microsoft windows 11 version 24h2
- microsoft windows 11 version 25h2
- microsoft windows 11 version 26h1
- microsoft windows server 2022
- microsoft windows server 2025
- microsoft windows server 2025 (server core installation)
- microsoft windows 10 21h2
- microsoft windows 10 22h2
- microsoft windows 11 23h2
Show 3 moreShow less
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | EUVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-42915 is a medium vulnerability (CVSS 5.5) in Microsoft Windows 10 Version 21h2, published June 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. No source names a fixed version.