---
id: CVE-2026-69304
title: >-
  Improper handling of highly compressed data (data amplification) in ASP.NET
  Core allows an unauthorized attacker to deny service over a network.
summary: >-
  Improper handling of highly compressed data (data amplification) in ASP.NET
  Core allows an unauthorized attacker to deny service over a network.
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-409
vendor: microsoft
product: asp.net_core
affected:
  - 'asp.net_core >= 8.0.0, < 8.0.28'
  - 'asp.net_core >= 9.0.0, < 9.0.17'
  - 'asp.net_core >= 10.0.0, < 10.0.9'
  - asp.net_core > 11.0.0
  - asp.net_core = 11.0
  - 'visual_studio_2022 >= 17.14.0, < 17.14.40'
  - 'visual_studio_2026 >= 18.9.0, < 18.9.3'
  - '.net >= 8.0.0, < 8.0.31'
  - '.net >= 9.0.0, < 9.0.20'
  - '.net >= 10.0.0, < 10.0.12'
patched:
  - asp.net_core 10.0.9
  - visual_studio_2022 17.14.40
  - visual_studio_2026 18.9.3
  - .net 10.0.12
published: '2026-09-08'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T20:49:06.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-69304'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69304'
    label: secure@microsoft.com
  - url: >-
      https://github.com/dotnet/aspnetcore/security/advisories/GHSA-8cp2-47hg-mfgh
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-69304'
  - url: 'https://github.com/advisories/GHSA-8cp2-47hg-mfgh'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-69304.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-69304'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2529952'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-69304'
  - url: 'https://access.redhat.com/errata/RHSA-2026:74950'
  - url: 'https://access.redhat.com/errata/RHSA-2026:74947'
  - url: 'https://access.redhat.com/errata/RHSA-2026:66863'
tags:
  - nvd
  - cve.org
  - ghsa
  - nuget
  - csaf
  - vex
  - red-hat
epss: 0.00855
epssPercentile: 0.58152
aliases:
  - GHSA-8cp2-47hg-mfgh
ecosystem: nuget
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T19:33:58.502592Z'
ingestedAt: '2026-09-08T19:08:49.608Z'
---

## Overview

Improper handling of highly compressed data (data amplification) in ASP.NET Core allows an unauthorized attacker to deny service over a network.

## Affected

- `asp.net_core >= 8.0.0, < 8.0.28`
- `asp.net_core >= 9.0.0, < 9.0.17`
- `asp.net_core >= 10.0.0, < 10.0.9`
- `asp.net_core > 11.0.0`
- `asp.net_core = 11.0`
- `visual_studio_2022 >= 17.14.0, < 17.14.40`
- `visual_studio_2026 >= 18.9.0, < 18.9.3`
- `.net >= 8.0.0, < 8.0.31`
- `.net >= 9.0.0, < 9.0.20`
- `.net >= 10.0.0, < 10.0.12`

## Remediation

Upgrade past the affected range:

- `asp.net_core 10.0.9`
- `visual_studio_2022 17.14.40`
- `visual_studio_2026 18.9.3`
- `.net 10.0.12`

## Package advisory (CVE-2026-69304)

Affected packages:

- `Microsoft.AspNetCore.Server.IISIntegration >= 11.0.0-preview.1, < 11.0.0-rc.1`
- `Microsoft.AspNetCore.Server.IISIntegration >= 8.0.0, <= 8.0.30`
- `Microsoft.AspNetCore.Server.IISIntegration >= 9.0.0, <= 9.0.19`
- `Microsoft.AspNetCore.Server.IISIntegration >= 10.0.0, <= 10.0.11`

Patched in:

- `Microsoft.AspNetCore.Server.IISIntegration 11.0.0-rc.1`
- `Microsoft.AspNetCore.Server.IISIntegration 8.0.31`
- `Microsoft.AspNetCore.Server.IISIntegration 9.0.20`
- `Microsoft.AspNetCore.Server.IISIntegration 10.0.12`

Source: https://github.com/advisories/GHSA-8cp2-47hg-mfgh

## Vendor advisories

- **RHSA-2026:74950** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-10-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:74950)
- **RHSA-2026:74947** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-10-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:74947)
- **RHSA-2026:66863** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:66863)