CVE-2026-42903: Windows Kerberos Denial of Service Vulnerability
Null pointer dereference in Windows Kerberos allows an authorized attacker to deny service over a network.
Other sources
Windows Kerberos Denial of Service Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23228Patch KB5094041 - Upgrade
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Fixed in 6.2.9200.26132Patch KB5094042 - Upgrade
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Fixed in 10.0.14393.9234Patch KB5094122 - Upgrade
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Fixed in 10.0.28000.2269Patch KB5095051 - Upgrade
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Fixed in 10.0.26100.32995Patch KB5094125 - Upgrade
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Fixed in 10.0.26100.8655Patch KB5094126 - Upgrade
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Fixed in 10.0.22631.7219Patch KB5093998 - Upgrade
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Fixed in 10.0.26200.8655Patch KB5094126 - Upgrade
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Fixed in 10.0.19045.7417Patch KB5094127 - Upgrade
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Fixed in 10.0.19044.7417Patch KB5094127 - Upgrade
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Fixed in 10.0.17763.8880Patch KB5094123 - Upgrade
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Fixed in 10.0.20348.5256Patch KB5094128
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42903?
CVE-2026-42903 has a medium severity rating of 6.5.
How do I fix CVE-2026-42903?
To address CVE-2026-42903, ensure that you have the latest security updates installed for affected Microsoft Windows versions.
What systems are affected by CVE-2026-42903?
CVE-2026-42903 affects Microsoft Windows 10, Windows 11, and various versions of Windows Server including 2012, 2016, 2019, 2022, and 2025.
What type of vulnerability is CVE-2026-42903?
CVE-2026-42903 is classified as a Denial of Service vulnerability due to a null pointer dereference.
What impact does CVE-2026-42903 have on systems?
CVE-2026-42903 allows an authorized attacker to deny service over a network by exploiting the vulnerability.