What is CVE-2026-40411?

CVE-2026-40411 is a critical-severity vulnerability in Microsoft Azure Virtual Network Gateway, classified under Improper Input Validation. CVSS score: 9.9/10. Published 2026-05-22.

How severe is CVE-2026-40411?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Improper input validation in Microsoft Azure Virtual Network Gateway

CVE-2026-40411

Improper input validation in Azure Virtual Network Gateway allows an authorized attacker to execute code over a network.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2026-05-22 · last modified 2026-07-23.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (60.1th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.010 · change: +0.004

Affected products

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

Azure Virtual Network Gateway Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-40411?: CVE-2026-40411 is a critical-severity vulnerability in Microsoft Azure Virtual Network Gateway, classified under Improper Input Validation. CVSS score: 9.9/10. Published 2026-05-22.
How severe is CVE-2026-40411?: Critical severity. CVSS v3 base score is 9.9 out of 10.