Security Update for Microsoft ASP.NET Core (July 2026)

high Nessus Plugin ID 326871

Synopsis

The Microsoft ASP.NET installations on the remote host are affected by multiple vulnerabilities.

Description

The Microsoft ASP.NET installations on the remote host are missing a security update. It is, therefore, affected by multiple vulnerabilities as referenced in the vendor advisory.

- Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network. (CVE-2026-47300)

- Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network. (CVE-2026-47303)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update ASP.NET Core, remove vulnerable packages and refer to vendor advisory.

Plugin Details

Severity: High

ID: 326871

File Name: smb_nt_ms26_jul_aspdotnet_core.nasl

Version: 1.2

Type: Local

Agent: windows

Family: Windows

Published: 7/14/2026

Updated: 7/15/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.11

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-47300

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2026-47303

Vulnerability Information

CPE: cpe:/a:microsoft:.net_core

Required KB Items: SMB/Registry/Enumerated, installed_sw/ASP .NET Core Windows

Exploit Ease: No known exploits are available

Patch Publication Date: 7/14/2026

Vulnerability Publication Date: 7/14/2026

Reference Information

CVE: CVE-2026-47300, CVE-2026-47303

Detections

Analytics