Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-83947

CVE-2026-83947MEDIUM

Microsoft Azure Event Grid System — Azure Event Grid Spoofing Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   N  U  N  H  N    6.5   .0036   28.5     —

AFFECTED
  Product                  Versions  Fixed
  Azure Event Grid System  - –       —

TIMELINE
  Aug 31  Reserved by microsoft
  Oct 8   Published (CNA: microsoft)
  Oct 15  RESCORED — CVE-2026-83947 (Microsoft Azure Event Grid System). CVSS 7.7 → 6.5 (NVD).

CWE-862 · CNA: microsoft · CVSS v3.1 · 1 reference · NVD status: Analyzed

Description

Missing authorization in Azure Event Grid allows an authorized attacker to perform spoofing over a network.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 31, 2026	Reserved	Reserved by microsoft
October 8, 2026	Published	Published (CNA: microsoft)
October 15, 2026	RESCORED	RESCORED — CVE-2026-83947 (Microsoft Azure Event Grid System). CVSS 7.7 → 6.5 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Microsoft	Azure Event Grid System	—	-	—

Weaknesses

CWE-862

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83947 [vendor-advisory, patch]

Authoritative record: CVE-2026-83947 at cve.org

Vendors: microsoft

Weaknesses: CWE-862

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-83947 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.