Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-77888Unknown / EvaluatingImportant (raw)CVSS 7.5
Windows DHCP Server Denial of Service Vulnerability
Published: 08 Sept 2026•Last updated: 08 Sept 2026, 12:30 PM IST•Source identifier: Unknown
Dossier completeness: source-provided sections 3 / 3 · rule guidance available. Missing source facts count as incomplete.
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
7.5Important (raw)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
1.2%0.012
Percentile67th
Weakness type
—
No further CWE recorded
Remediation
Patch status unknown
KB5122876, KB5122882, KB5122871, KB5123099, KB5123065, KB5123066
Why It Matters
Analysis dossierWhy It Matters
Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network.
SOC priority
Medium
Actively exploited
No
Publicly disclosed
Unknown
Risk basis: No confirmed exploitation signal in current enrichment
Affected Products & Remediation
16 source-backed productsAffected products and versions (source)
- Windows 10 Version 1809 for 32-bit Systems · version range not provided by source · Microsoft MSRC · Source
- Windows 10 Version 1809 for x64-based Systems · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2019 · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2019 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2022 · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2022 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2025 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2025 · version range not provided by source · Microsoft MSRC · Source
- Windows 10 Version 1607 for 32-bit Systems · version range not provided by source · Microsoft MSRC · Source
- Windows 10 Version 1607 for x64-based Systems · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2016 · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2016 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2012 · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2012 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2012 R2 · version range not provided by source · Microsoft MSRC · Source
- Windows Server 2012 R2 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBKB5122876, KB5122882, KB5122871, KB5123099, KB5123065, KB5123066
Vendor or catalog guidance (source)
- Microsoft MSRC: Install the security update KB5122876 listed by MSRC
- Microsoft MSRC: Install the security update KB5122882 listed by MSRC
- Microsoft MSRC: Install the security update KB5122871 listed by MSRC
- Microsoft MSRC: Install the security update KB5123099 listed by MSRC
- Microsoft MSRC: Install the security update KB5123065 listed by MSRC
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Unknown
- Exploited (source statement)
- No
- Publicly disclosed (source)
- Unknown
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
Matched microsoft-enterprise (Affected product: Windows 10 Version 1809 for 32-bit Systems, Vendor: Microsoft); network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)
Exposure
- Identify affected Microsoft products and compare local builds with the MSRC advisory.Telemetry: DeviceTvmSoftwareVulnerabilities · The MSRC product/build mapping establishes applicability. · Rule microsoft-enterprise
- Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated
Exploitation evidence
- Review the advisory's documented behavior on matching hosts before selecting a hunt.Telemetry: DeviceProcessEvents · Product family alone does not justify a CVE-specific detection. · Rule microsoft-enterprise
Show more (2)
Exploitation evidence
- Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated
Response
- Confirm the source-stated KB or mitigation on matching assets.Telemetry: DeviceTvmSoftwareVulnerabilities · A post-update inventory check verifies remediation. · Rule microsoft-enterprise
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- Unknown
- Record status · verification
- UPDATED · Unknown
- CPE
- Unknown
Evidence & Provenance
Detection Hunting Query
— No published hunting query names this record. Browse community and library queries instead.
Correlated briefings
SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.