EUVD-2026-35726
GHSA-3hrv-h2gx-w5g3
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
2DescriptionCVE.org
Windows Kerberos Denial of Service Vulnerability
AnalysisAI
Windows Kerberos out-of-bounds read (CWE-125) allows a low-privilege network attacker to crash the Kerberos authentication service across all actively supported Windows client and server platforms, from Windows Server 2012 through Windows Server 2025 and Windows 11 26H1. The attack requires prior domain authentication and high-complexity triggering conditions (CVSS AC:H), limiting opportunistic mass exploitation, though a successful attack against a domain controller can deny authentication domain-wide by crashing the KDC. Vendor patches are available via the Microsoft MSRC advisory; no public exploit code exists and SSVC confirms no observed exploitation at time of analysis.
Technical ContextAI
The vulnerability resides in Microsoft's Windows Kerberos implementation, which handles network authentication across Active Directory and domain-joined systems using the Kerberos v5 protocol over TCP/UDP port 88. CWE-125 (Out-of-bounds Read) indicates the parser reads beyond an allocated buffer boundary when processing attacker-controlled data - likely in authentication exchange messages such as AS-REQ, TGS-REQ, or related key exchange structures. Notably, the intelligence tags include both 'Buffer Overflow' and 'Information Disclosure' alongside the primary DoS classification, yet the CVSS impact scores record C:N and I:N, meaning only availability impact is formally assessed. Affected CPE scope spans NT builds from 6.2.9200 (Windows Server 2012) through 10.0.28000 (Windows 11 26H1), covering every major Windows release family still in common enterprise use. The unchanged scope (S:U) confirms the out-of-bounds read is contained within the Kerberos service process boundary rather than escaping to the hypervisor or other security domains.
RemediationAI
Vendor-released patches are available for all affected platforms via the Microsoft Security Response Center at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42914. Organizations should update to the following minimum build versions confirmed by EUVD-2026-35726: Windows 10 1607 and Server 2016 to 10.0.14393.9234; Windows 10 1809 and Server 2019 to 10.0.17763.8880; Windows 10 21H2 to 10.0.19044.7417 and 22H2 to 10.0.19045.7417; Windows 11 23H2 to 10.0.22631.7219; Windows 11 24H2 and 25H2 to 10.0.26100.8655; Windows 11 26H1 to 10.0.28000.2269; Server 2012 to 6.2.9200.26132; Server 2012 R2 to 6.3.9600.23228; Server 2022 to 10.0.20348.5256; and Server 2025 to 10.0.26100.32995. As a compensating control prior to patching, restrict inbound Kerberos traffic (TCP/UDP port 88) on domain controllers to trusted internal subnet ranges only - note this will block authentication requests from unwhitelisted network segments and may impact remote access scenarios. Additionally, enabling alerting on unexpected restarts of the Kerberos Distribution Center service provides early detection of exploitation attempts.
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Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Denial Of Service
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External POC / Exploit Code
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