---
id: CVE-2026-97801
title: >-
  Improper validation of specified type of input in .NET Framework allows an
  unauthorized attacker to perform tampering over a network.
summary: >-
  Improper validation of specified type of input in .NET Framework allows an
  unauthorized attacker to perform tampering over a network.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-1287
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T23:19:33.740'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97801'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97801'
    label: secure@microsoft.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97801.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-97801'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2551867'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97801'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97801'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-13T19:43:29.308Z'
vendor: Microsoft
product: Microsoft .NET Framework 3.5
affected:
  - .net_framework_3.5 >= 3.5.0 < 2.0.50727.9188 AND 3.0.30729.9171
  - >-
    .net_framework_3.5_and_4.6.2_4.7_4.7.1_4.7.2 >= 3.0.0.0 < 2.0.50727.8987 AND
    3.0.30729.8982 AND 4.7.4150.0
  - >-
    .net_framework_3.5_and_4.7.2 >= 4.7.0 < 2.0.50727.9073 AND 3.0.30729.9070
    AND 4.7.4150.0
  - >-
    .net_framework_3.5_and_4.8 >= 4.8.0 < 2.0.50727.9073 AND 3.0.30729.9070 AND
    4.8.4811.0
  - >-
    .net_framework_3.5_and_4.8.1 >= 4.8.1 < 2.0.50727.9188 AND 3.0.30729.9171
    AND 4.8.9363.0
  - .net_framework_4.6.2_4.7_4.7.1_4.7.2 >= 4.7.0 < 4.7.4150.0
  - .net_framework_4.8 >= 4.8.0 < 4.8.4811.0
  - .net_framework_4.8.1 >= 4.8.0.0 < 4.8.9363.0
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-13T22:14:29.433528Z'
epss: 0.00734
epssPercentile: 0.5419
---

## Overview

Improper validation of specified type of input in .NET Framework allows an unauthorized attacker to perform tampering over a network.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97801.json)