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Vulnerabilities/CVE-2026-83947Public Intelligence Dossier
Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-83947Unknown / EvaluatingCritical (raw)CVSS 7.7CWE-862

Azure Event Grid Spoofing Vulnerability

Published: 08 Oct 2026•Last updated: 08 Oct 2026, 12:30 PM IST•Source identifier: secure@microsoft.com
Dossier completeness: source-provided sections 2 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
7.7Critical (raw)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.4%0.004
Percentile28th
Weakness type
CWE-862
No further CWE recorded
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

Missing authorization in Azure Event Grid allows an authorized attacker to perform spoofing 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

1 source-backed product
Affected products and versions (source)
  • Azure Event Grid System · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

Not provided by source

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 authorization-bypass (CWE-862)

Exposure

  1. Locate affected authorization controls and verify deployed versions.Telemetry: Application inventory · The source must identify the affected control. · Rule authorization-bypass

Exploitation evidence

  1. Review privileged operations performed by unexpected users on affected deployments.Telemetry: Application audit logs · Authorization anomalies can support a targeted hunt. · Rule authorization-bypass

Response

  1. Confirm the vendor mitigation and recheck access decisions.Telemetry: Application audit logs · Access testing verifies the local fix. · Rule authorization-bypass

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:azure_event_grid:-:*:*:*:*:*:*:*

Evidence & Provenance

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

— No published hunting query names this record. Browse community and library queries instead.

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.