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Vulnerabilities/CVE-2026-88122Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-88122Unknown / EvaluatingImportant (raw)CVSS 6.5CWE-125

Role: DNS Server Denial of Service Vulnerability

Published: 13 Oct 2026•Last updated: 13 Oct 2026, 12:30 PM IST•Source identifier: secure@microsoft.com
Dossier completeness: source-provided sections 3 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
6.5Important (raw)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.8%0.008
Percentile55th
Weakness type
CWE-125
No further CWE recorded
Remediation
Patch status unknown
KB5126835, KB5126836, KB5126868, KB5126651, KB5126655, KB5126646

Why It Matters

Analysis dossier

Why It Matters

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

SOC priority

Medium

Actively exploited

No

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; No confirmed exploitation signal in current enrichment

Affected Products & Remediation

12 source-backed products
Affected products and versions (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
  • 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 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 · version range not provided by source · Microsoft MSRC · Source
  • Windows Server 2025 (Server Core installation) · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBKB5126835, KB5126836, KB5126868, KB5126651, KB5126655, KB5126646

Vendor or catalog guidance (source)

  • Microsoft MSRC: Install the security update KB5126835 listed by MSRC
  • Microsoft MSRC: Install the security update KB5126836 listed by MSRC
  • Microsoft MSRC: Install the security update KB5126868 listed by MSRC
  • Microsoft MSRC: Install the security update KB5126651 listed by MSRC
  • Microsoft MSRC: Install the security update KB5126655 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 Server 2012, Vendor: Microsoft)

Exposure

  1. Identify affected Microsoft products and compare local builds with the MSRC advisory.Telemetry: DeviceTvmSoftwareVulnerabilities · The MSRC product/build mapping establishes applicability. · Rule microsoft-enterprise

Exploitation evidence

  1. 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

Response

  1. 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
secure@microsoft.com
Record status · verification
UPDATED · Unknown
CPE
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*, cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*, cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*, cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*, cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*, cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

Evidence & Provenance

3 public sources
msrc.microsoft.comSource recordapi.msrc.microsoft.comSource recordnvd.nist.govSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2026-88122
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-88122
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-88122"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library

Correlated briefings

Microsoft Security Update Guide · Limited verificationOctober 2026 Security UpdatesPublished 13 Oct 2026
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.