CVE-2026-47300

ASP.NET Core Elevation of Privilege Vulnerability

Published Jul 14, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed

Description

Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Analysis

Technical impact

The flaw stems from an incorrect implementation of the authentication algorithm in ASP.NET Core, allowing an attacker who already has authorized access to raise their privileges across the network. This produces an elevation of privilege condition. The weakness is classified as CWE-303, an authentication bypass vulnerability.

Affected Systems

Microsoft .NET 10.0, 9.0 and 8.0, as well as Microsoft Visual Studio 2022 versions 17.12 and 17.14, and Microsoft Visual Studio 2026 version 18.7, should be checked against the vendor’s advisory for the applicable patches.

Risk and Exploitability

With a CVSS score of 8.8 the vulnerability is considered High severity. The EPSS score of less than 1% indicates a low probability of exploitation at present, and the issue is not listed in the CISA KEV catalog. Likely attack scenarios involve an attacker who has legitimate credentials targeting a networked ASP.NET Core application; exploiting the faulty algorithm can elevate privileges without additional access rights.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Microsoft

.NET 10.0 runtime

affected

Version	Status	Constraints
`10.0.0`	affected	< 10.0.10

Microsoft

.NET 8.0 runtime

affected

Version	Status	Constraints
`8.0.0`	affected	< 8.0.29

Microsoft

.NET 9.0 runtime

affected

Version	Status	Constraints
`9.0.0`	affected	< 9.0.18

Microsoft

Microsoft Visual Studio 2022 version 17.12

affected

Version	Status	Constraints
`17.12.0`	affected	< 17.12.22

Microsoft

Microsoft Visual Studio 2022 version 17.14

affected

Version	Status	Constraints
`17.14.0`	affected	< 17.14.36

Microsoft

Microsoft Visual Studio 2026 version 18.7

affected

Version	Status	Constraints
`18.0`	affected	< 18.7.4

Configuration 1 [-]

AND

OR	cpe:2.3:a:microsoft:.net::::::::
	cpe:2.3:a:microsoft:.net::::::::

OR	cpe:2.3:o:apple:macos:-:::::::*
	cpe:2.3:o:linux:linux_kernel:-:::::::*
	cpe:2.3:o:microsoft:windows:-:::::::*

Configuration 2 [-]

AND

cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

OR	cpe:2.3:o:apple:macos:-:::::::*
	cpe:2.3:o:linux:linux_kernel:-:::::::*

Configuration 3 [-]

OR	cpe:2.3:a:microsoft:visual_studio_2022::::::::
	cpe:2.3:a:microsoft:visual_studio_2022::::::::
	cpe:2.3:a:microsoft:visual_studio_2026::::::::

Package	CPE	Advisory	Released Date
Red Hat Hardened Images
dotnet10-0-main-10.0.109-1.hum1	cpe:/a:redhat:hummingbird:1	RHSA-2026:26638	2026-06-17T00:00:00Z
dotnet9-0-main-9.0.119-1.hum1	cpe:/a:redhat:hummingbird:1	RHSA-2026:39952	2026-07-15T00:00:00Z

Vendor Product Versions

Microsoft

.net

Version	Status	Scheme	Platform
`[10.0.0,10.0.6)`	affected	semver	—
`[8.0.0,8.0.29)`	affected	semver	—
`[9.0.0,9.0.18)`	affected	semver	—

Microsoft

.net

Version	Status	Scheme	Platform
`[10.0.0,10.0.6)`	affected	semver	—

Microsoft

.net

Version	Status	Scheme	Platform
`[8.0.0,8.0.29)`	affected	semver	—

Microsoft

.net

Version	Status	Scheme	Platform
`[9.0.0,9.0.18)`	affected	semver	—

Microsoft

Microsoft Visual Studio 2022

Version	Status	Scheme	Platform
`[17.12.0,17.12.22)`	affected	semver	—

Microsoft

Microsoft Visual Studio 2022

Version	Status	Scheme	Platform
`[17.14.0,17.14.36)`	affected	semver	—

Microsoft

Microsoft Visual Studio 2026

Version	Status	Scheme	Platform
`[18.0,18.7.4)`	affected	generic	—

Microsoft

Visual Studio 2022

Version	Status	Scheme	Platform
`[17.12.0,17.12.22)`	affected	semver	—
`[17.14.0,17.14.36)`	affected	semver	—

Microsoft

Visual Studio 2026

Version	Status	Scheme	Platform
`[18.0,18.7.4)`	affected	generic	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Download and install the latest Microsoft security update for the affected .NET and Visual Studio components as detailed in the MSRC advisory.
Ensure that ASP.NET Core authentication middleware is configured according to Microsoft’s recommended best‑practice settings, and validate that no custom code bypasses the framework’s authentication flow.
Apply the principle of least privilege by restricting privileged accounts and roles until a vendor patch is applied, and monitor authentication events for unexpected privilege changes.

Generated by OpenCVE AI on July 31, 2026 at 05:47 UTC.

Tracking

Advisories

Source	ID	Title
Github GHSA	GHSA-8prm-248r-h957	Microsoft Security Advisory CVE-2026-47300 – .NET Elevation of Privilege Vulnerability
Ubuntu USN	USN-8553-1	.NET vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.778% probability within 30 days)

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47300
https://nvd.nist.gov/vuln/detail/CVE-2026-47300
https://www.cve.org/CVERecord?id=CVE-2026-47300

History

Aug 7, 2026 11:45 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Microsoft microsoft Visual Studio 2022 Microsoft microsoft Visual Studio 2026
Vendors & Products		Microsoft microsoft Visual Studio 2022 Microsoft microsoft Visual Studio 2026

Jul 18, 2026 12:15 PM First appearance in the feed. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
First Time appeared		Redhat Redhat hummingbird
CPEs		cpe:/a:redhat:hummingbird:1
Vendors & Products		Redhat Redhat hummingbird
References		https://nvd.nist.gov/vuln/detail/CVE-2026-47300 https://www.cve.org/CVERecord?id=CVE-2026-47300
Metrics	threat_severity `None`	threat_severity `Important`

Jul 15, 2026 11:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Jul 14, 2026 6:45 PM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Title		ASP.NET Core Elevation of Privilege Vulnerability
First Time appeared		Microsoft Microsoft .net Microsoft visual Studio 2022 Microsoft visual Studio 2026
Weaknesses		CWE-303
CPEs		cpe:2.3:a:microsoft:.net:::::::: cpe:2.3:a:microsoft:visual_studio_2022:::::::: cpe:2.3:a:microsoft:visual_studio_2026::::::::
Vendors & Products		Microsoft Microsoft .net Microsoft visual Studio 2022 Microsoft visual Studio 2026
References		https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47300
Metrics		cvssV3_1 `{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'}`