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Vulnerabilities/CVE-2026-102870Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-102870Unknown / EvaluatingImportant (raw)CVSS 8.8CWE-94

ASP.NET Core Remote Code Execution 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
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
Percentile55th
Weakness type
CWE-94
No further CWE recorded
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.

SOC priority

Review

Actively exploited

No

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; HIGH severity

Affected Products & Remediation

8 source-backed products
Affected products and versions (source)
  • Microsoft Visual Studio 2026 version 18.10 · 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.AspNetCore.Components.WebAssembly.Server on .NET 10.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 10.0 installed on Linux · version range not provided by source · Microsoft MSRC · Source
  • Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 10.0 installed on Mac OS · version range not provided by source · Microsoft MSRC · Source
  • Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 11.0 installed on Windows · version range not provided by source · Microsoft MSRC · Source
  • Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 11.0 installed on Linux · version range not provided by source · Microsoft MSRC · Source
  • Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 11.0 installed on Mac OS · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

  • Microsoft MSRC: Release Notes

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: Microsoft.AspNetCore.Components.WebAssembly.Server on .NET 10.0 installed on Windows, Vendor: Microsoft); user-interaction-client (CVSS AV:N, CVSS UI:R)

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. Identify endpoints reporting this CVE, especially those used for email and web browsing.Telemetry: DeviceTvmSoftwareVulnerabilities · A network vector that needs user interaction points at user-facing client software. · Rule user-interaction-client

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 started by the affected client application on affected endpoints.Telemetry: DeviceProcessEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule user-interaction-client

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-2026-102870
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-102870
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-102870"| 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.