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Vulnerabilities/CVE-2026-87697Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Running
CVE-2026-87697Unknown / EvaluatingImportant (raw)CVSS 8.8CWE-502

.NET Remote Code Execution Vulnerability

Published: 13 Oct 2026•Last updated: 15 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
8.8Important (raw)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.8%0.008
Percentile57th
Weakness type
CWE-502
No further CWE recorded
Remediation
Patch status unknown
KB5130036, KB5130034, KB5130035

Why It Matters

Analysis dossier

Why It Matters

Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code over a network.

SOC priority

High

Actively exploited

No

Publicly disclosed

Unknown

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

Affected Products & Remediation

6 source-backed products
Affected products and versions (source)
  • .NET 11.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • .NET 10.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • .NET 8.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • .NET 9.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • Microsoft Visual Studio 2022 version 17.14 · version range not provided by source · Microsoft MSRC · Source
  • Microsoft Visual Studio 2026 version 18.10 · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBKB5130036, KB5130034, KB5130035

Vendor or catalog guidance (source)

  • Microsoft MSRC: Release Notes
  • Microsoft MSRC: Install the security update KB5130036 listed by MSRC
  • Microsoft MSRC: Install the security update KB5130034 listed by MSRC
  • Microsoft MSRC: Install the security update KB5130035 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: .NET 11.0 installed on Windows, Vendor: Microsoft); deserialization (CWE-502)

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
  2. Find installations of the affected component and confirm the source-stated version range.Telemetry: Application inventory · Deserialization risk requires component and version evidence. · Rule deserialization

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
Show more (2)

Exploitation evidence

  1. Review unusual child processes or network connections from the affected service.Telemetry: DeviceProcessEvents · Unexpected behavior may support investigation but is not proof by itself. · Rule deserialization

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
Unknown

Evidence & Provenance

3 public sources
api.msrc.microsoft.comSource recordnvd.nist.govSource recordmsrc.microsoft.comSource 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-2026-87697
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-87697
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-87697"| 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.