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CVE-2026-119890: Windows DHCP Server Denial of Service Vulnerability

CVE-2026-119890 is a denial of service vulnerability in Windows DHCP Server, rated Important by Microsoft, with a CVSS 3.1 base score of 5.3 (Medium). An attacker can exploit it remotely over the network, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday, delivered through 5 security updates (KB5131291, KB5131085, KB5131090, KB5131080 and more). It affects 8 products in 2 product families (ESU, Windows).

Key facts

CVE ID
CVE-2026-119890
Severity
Medium CVSS 5.3
Microsoft severity
Important
Impact
Denial of Service
Exploited in the wild
No
Publicly disclosed
No
Exploitation likelihood
Less Likely
Weakness
CWE-125
CISA KEV
Not listed
Released
Last updated
Patch Tuesday
November 2026 Patch Tuesday
Product families
ESU, Windows

CVSS score and vector

Microsoft scores CVE-2026-119890 at 5.3 (temporal 4.6) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

MetricValue
Attack vectorNetwork
Attack complexityHigh
Privileges requiredLow
User interactionNone
ScopeUnchanged
Confidentiality impactNone
Integrity impactNone
Availability impactHigh
Exploit code maturityUnproven
Remediation levelOfficial fix
Report confidenceConfirmed

Description

Out-of-bounds read in Windows DHCP Server allows an authorized attacker to deny service over a network.

Affected products (8)

ESU

ProductSecurity updateTypeFixed buildRestart
Windows Server 2016KB5131291Security Update10.0.14393.9688Yes
Windows Server 2016 (Server Core installation)KB5131291Security Update10.0.14393.9688Yes

Windows

ProductSecurity updateTypeFixed buildRestart
Windows Server 2019KB5131085Security Update10.0.17763.9487Yes
Windows Server 2019 (Server Core installation)KB5131085Security Update10.0.17763.9487Yes
Windows Server 2022KB5131090Security Update10.0.20348.5870Yes
Windows Server 2022 (Server Core installation)KB5131090Security Update10.0.20348.5870Yes
Windows Server 2025KB5131080
KB5131077		Security Update
Security Hotpatch Update		10.0.26100.33822
10.0.26100.33730		Yes
No
Windows Server 2025 (Server Core installation)KB5131080
KB5131077		Security Update
Security Hotpatch Update		10.0.26100.33822
10.0.26100.33730		Yes
No

Security updates (5)

NIST NVD data

NVD status
Awaiting Analysis
NVD CVSS
5.3 (MEDIUM)
NVD weakness
CWE-125
Published to NVD
NVD last modified

References

Acknowledgments

  • Anonymous

Revision history

VersionDateDescription
1.0Information published.

Sources