---
id: CVE-2026-40372
title: >-
  Improper verification of cryptographic signature in ASP.NET Core allows an
  unauthorized attacker to elevate privileges over a network.
summary: >-
  Improper verification of cryptographic signature in ASP.NET Core allows an
  unauthorized attacker to elevate privileges over a network.
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-347
  - CWE-347
published: '2026-04-21'
updated: '2026-06-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40372'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40372'
    label: secure@microsoft.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-40372'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2460224'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40372.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
epss: 0.11205
epssPercentile: 0.95819
ingestedAt: '2026-06-29T13:24:34.826Z'
---

## Overview

Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.