What is CVE-2026-83947?

CVE-2026-83947 is a high-severity vulnerability in Microsoft Azure Event Grid System, classified under Missing Authorization. CVSS score: 7.7/10. Published 2026-10-08.

How severe is CVE-2026-83947?

High severity. CVSS v3 base score is 7.7 out of 10.

Auth bypass in Microsoft Azure Event Grid System

CVE-2026-83947

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

Vulnerability class: Broken Access Control

Published 2026-10-08 · last modified 2026-10-09.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Microsoft Azure Event Grid System

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83947 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-83947?: CVE-2026-83947 is a high-severity vulnerability in Microsoft Azure Event Grid System, classified under Missing Authorization. CVSS score: 7.7/10. Published 2026-10-08.
How severe is CVE-2026-83947?: High severity. CVSS v3 base score is 7.7 out of 10.