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Vulnerabilities/CVE-2026-85340Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-85340Unknown / EvaluatingImportant (raw)CVSS 7.8CWE-416

Microsoft Office Click-To-Run Elevation of Privilege 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
7.8Important (raw)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.3%0.003
Percentile23rd
Weakness type
CWE-416
No further CWE recorded
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

Use after free in Microsoft Office Click-To-Run allows an authorized attacker to elevate privileges locally.

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)
  • Microsoft Office LTSC 2021 for 64-bit editions · version range not provided by source · Microsoft MSRC · Source
  • Microsoft Office LTSC 2021 for 32-bit editions · version range not provided by source · Microsoft MSRC · Source
  • Microsoft Office LTSC 2024 for 64-bit editions · version range not provided by source · Microsoft MSRC · Source
  • Microsoft Office LTSC 2024 for 32-bit editions · version range not provided by source · Microsoft MSRC · Source
  • Microsoft 365 Apps for Enterprise for 64-bit Systems · version range not provided by source · Microsoft MSRC · Source
  • Microsoft 365 Apps for Enterprise for 32-bit Systems · 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 local-privilege-escalation (CVSS AV:L, CVSS PR:L)

Exposure

  1. Identify hosts reporting this CVE, prioritising shared or multi-user systems.Telemetry: DeviceTvmSoftwareVulnerabilities · A local, low-privilege vector matters most where untrusted users can run code. · Rule local-privilege-escalation

Exploitation evidence

  1. Look for low-privileged processes spawning SYSTEM or root-level child processes on affected hosts.Telemetry: DeviceProcessEvents · Hunting hypothesis from the CVSS vector; privilege transitions are a focused starting point, not evidence of attack. · Rule local-privilege-escalation

Response

  1. Confirm the source-stated update on affected hosts.Telemetry: DeviceTvmSoftwareVulnerabilities · Host inventory can verify remediation. · Rule local-privilege-escalation

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:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*, cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*, cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*, cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*, cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*, cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*

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-2026-85340
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-85340
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-85340"| 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.