What is CVE-2026-42903?

CVE-2026-42903 is a medium-severity vulnerability in Microsoft Windows_10_1607, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-06-09.

How severe is CVE-2026-42903?

Medium severity. CVSS v3 base score is 6.5 out of 10.

NULL pointer dereference in Microsoft Windows_10_1607

CVE-2026-42903

Null pointer dereference in Windows Kerberos allows an authorized attacker to deny service over a network.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Microsoft Windows_10_1607
Microsoft Windows_10_1809
Microsoft Windows_10_21h2
Microsoft Windows_10_22h2
Microsoft Windows_11_23h2
Microsoft Windows_11_24h2
Microsoft Windows_11_25h2
Microsoft Windows_11_26h1
Microsoft Windows_server_2012 — versions r2
Microsoft Windows_server_2016

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

secure@microsoft.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-42903?: CVE-2026-42903 is a medium-severity vulnerability in Microsoft Windows_10_1607, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-06-09.
How severe is CVE-2026-42903?: Medium severity. CVSS v3 base score is 6.5 out of 10.