CVE-2026-42915: Windows TCP/IP Denial of Service Vulnerability
Published Jun 9, 2026
·Updated
Incorrect calculation of buffer size in Windows TCP/IP allows an authorized attacker to deny service over an adjacent network.
Other sources
Windows TCP/IP Denial of Service Vulnerability
— Microsoft
Affected Software
35 affected componentsFixes available
Microsoft Windows TCP/IP Stack
Microsoft Windows 10=22H2
Microsoft Windows 10=22H2
Microsoft Windows Server 2025
Microsoft Windows 10=22H2
Microsoft Windows 10=21H2
Microsoft Windows 11=26H1
Microsoft Windows Server 2022
Microsoft Windows 11=24H2
Microsoft Windows 11=26H1
Microsoft Windows Server 2025
Microsoft Windows 11=23H2
Microsoft Windows 11=25H2
Microsoft Windows 11=25H2
Microsoft Windows 11=23H2
Microsoft Windows 11=24H2
Microsoft Windows 10=21H2
Microsoft Windows Server 2022
Microsoft Windows 10=21H2
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 11 23h2<10.0.22631.7219
Microsoft Windows 11 23h2<10.0.22631.7219
Microsoft Windows 11 24h2<10.0.26100.8655
Microsoft Windows 11 24h2<10.0.26100.8655
Microsoft Windows 11 25h2<10.0.26200.8655
Microsoft Windows 11 25h2<10.0.26200.8655
Microsoft Windows 11 26h1<10.0.28000.2269
Microsoft Windows 11 26h1<10.0.28000.2269
Microsoft Windows Server 2022<10.0.20348.5256
Microsoft Windows Server 2025<10.0.26100.32995
Event History
Jun 9, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:06 PM
Data Sourced
via MITRE·05:06 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-42915?
CVE-2026-42915 has a medium severity rating, scoring 5.7 on the CVSS scale.
2
What systems are affected by CVE-2026-42915?
CVE-2026-42915 affects Microsoft Windows 10, Windows 11, Windows Server 2022, Windows Server 2025, and the Microsoft Windows TCP/IP Stack.
3
How can I mitigate the risk of CVE-2026-42915?
To mitigate CVE-2026-42915, apply the latest updates and patches provided by Microsoft for the affected systems.
4
What type of attack does CVE-2026-42915 enable?
CVE-2026-42915 allows an authorized attacker to launch a denial of service attack over an adjacent network.
5
What causes CVE-2026-42915?
CVE-2026-42915 is caused by an incorrect calculation of buffer size in the Windows TCP/IP protocol stack.