CVE-2026-42904: Windows TCP/IP Elevation of Privilege Vulnerability

Published Jun 9, 2026
·
Updated

Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.

Other sources

Windows TCP/IP Elevation of Privilege Vulnerability

Microsoft

Affected Software

35 affected componentsFixes available
Microsoft Windows TCP/IP
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
Microsoft Windows 11=23H2
10.0.22631.7219
Microsoft Windows 11=25H2
10.0.26200.8655
Microsoft Windows 11=23H2
10.0.22631.7219
Microsoft Windows 11=25H2
10.0.26200.8655
Microsoft Windows Server 2025<10.0.26100.32995
10.0.26100.32995
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 10=21H2
10.0.19044.7417
Microsoft Windows 10=21H2
10.0.19044.7417
Microsoft Windows Server 2022<10.0.20348.5256
10.0.20348.5256
Microsoft Windows 10=21H2
10.0.19044.7417
Microsoft Windows Server 2022<10.0.20348.5256
10.0.20348.5256
Microsoft Windows 11=26H1
10.0.28000.2269
Microsoft Windows 11=26H1
10.0.28000.2269
Microsoft Windows 11=24H2
10.0.26100.8655
Microsoft Windows Server 2025<10.0.26100.32995
10.0.26100.32995
Microsoft Windows 11=24H2
10.0.26100.8655

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.22631.7219Patch KB5093998
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26200.8655Patch KB5094126
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.32995Patch KB5094125
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19045.7417Patch KB5094127
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19044.7417Patch KB5094127
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.20348.5256Patch KB5094128
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.28000.2269Patch KB5095051
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.8655Patch KB5094126

Event History

Jun 9, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
DescriptionWeakness
CVE Published
via MITRE·05:05 PM
Data Sourced
via MITRE·05:05 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-42904?

The severity of CVE-2026-42904 is critical, with a CVSS score of 9.6.

2

How do I fix CVE-2026-42904?

To fix CVE-2026-42904, apply the latest security updates provided by Microsoft for affected versions of Windows.

3

Who is affected by CVE-2026-42904?

CVE-2026-42904 affects users of Microsoft Windows 10, Windows 11, and Windows Server 2022 and 2025.

4

What type of vulnerability is CVE-2026-42904?

CVE-2026-42904 is classified as a heap-based buffer overflow vulnerability.

5

What could an attacker achieve by exploiting CVE-2026-42904?

An attacker could elevate privileges on the affected system over an adjacent network by exploiting CVE-2026-42904.

Contact

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