---
id: CVE-2021-31957
title: ASP.NET Core Denial of Service Vulnerability
summary: ASP.NET Core Denial of Service Vulnerability
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-400
vendor: microsoft
product: .net
affected:
  - '.net >= 5.0, <= 5.0.6'
  - '.net_core >= 3.1, <= 3.1.15'
  - 'visual_studio_2019 >= 16.0, <= 16.10'
  - visual_studio_2019 = 8.10
  - fedora = 33
  - fedora = 34
published: '2021-06-08'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T17:16:42.677'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-31957'
references:
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4PRVVLXXQEF4SEJOBV3VRJHGX7YHY2CG/
    label: secure@microsoft.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVCDYIP4A6DDRT7G6P3ZW6PKNK2DNWJ2/
    label: secure@microsoft.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PMHWHRRYDHKM6BIINW5V7OCSW4SDWB4W/
    label: secure@microsoft.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VMAO4NG2OQ4PCXUQWMNSCMYWLIJJY6UY/
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31957
    label: secure@microsoft.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4PRVVLXXQEF4SEJOBV3VRJHGX7YHY2CG/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVCDYIP4A6DDRT7G6P3ZW6PKNK2DNWJ2/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PMHWHRRYDHKM6BIINW5V7OCSW4SDWB4W/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VMAO4NG2OQ4PCXUQWMNSCMYWLIJJY6UY/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31957
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-07T16:11:27.626727Z'
epss: 0.05138
epssPercentile: 0.92183
ingestedAt: '2026-10-07T16:38:22.254Z'
---

## Overview

ASP.NET Core Denial of Service Vulnerability

## Affected

- `.net >= 5.0, <= 5.0.6`
- `.net_core >= 3.1, <= 3.1.15`
- `visual_studio_2019 >= 16.0, <= 16.10`
- `visual_studio_2019 = 8.10`
- `fedora = 33`
- `fedora = 34`

## Remediation

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