CVE-2026-114146: ASP.NET Core Elevation of Privilege Vulnerability
CVE-2026-114146 is an elevation of privilege vulnerability in ASP.NET Core, rated Important by Microsoft, with a CVSS 3.1 base score of 9 (Critical). An attacker can exploit it remotely over the network, with low privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday, delivered through 3 security updates (KB5135243, KB5135242, KB5135241). It affects 16 products in 2 product families (Other, Developer Tools).
Key facts
- CVE ID
- CVE-2026-114146
- Severity
- Critical CVSS 9
- Microsoft severity
- Important
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Other, Developer Tools
CVSS score and vector
Microsoft scores CVE-2026-114146 at 9 (temporal 7.8) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | Required |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Incorrect authorization in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
How could an attacker exploit this vulnerability?
An authenticated attacker could convince a privileged user to follow a specially crafted link to an affected application. Successful exploitation could allow the attacker to perform actions with that user's application privileges.
Affected products (16)
Other
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft.AspNetCore.Http.Connections | Release Notes | Security Update | 1.2.14 |
Developer Tools
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| .NET 8.0 installed on Windows | KB5135243 | Security Update | 8.0.34 | |
| .NET 8.0 installed on Linux | KB5135243 | Security Update | 8.0.34 | |
| .NET 8.0 installed on Mac OS | KB5135243 | Security Update | 8.0.34 | |
| .NET 9.0 installed on Windows | KB5135242 | Security Update | 9.0.23 | |
| .NET 9.0 installed on Linux | KB5135242 | Security Update | 9.0.23 | |
| .NET 9.0 installed on Mac OS | KB5135242 | Security Update | 9.0.23 | |
| .NET 10.0 installed on Windows | KB5135241 | Security Update | 10.0.15 | |
| .NET 10.0 installed on Linux | KB5135241 | Security Update | 10.0.15 | |
| .NET 10.0 installed on Mac OS | KB5135241 | Security Update | 10.0.15 | |
| .NET 11.0 installed on Windows | Release Notes | Security Update | 11.0.0 | |
| .NET 11.0 installed on Linux | Release Notes | Security Update | 11.0.0 | |
| .NET 11.0 installed on Mac OS | Release Notes | Security Update | 11.0.0 | |
| Microsoft Visual Studio 2022 version 17.14 | Release Notes | Security Update | 17.14.45 | Yes |
| Microsoft Visual Studio 2026 version 18.11 | Release Notes | Security Update | 18.11.4 | |
| Microsoft Visual Studio 2026 version 18.12 | Release Notes | Security Update | 18.12.0 |
Security updates (3)
Acknowledgments
- Vu Van Tien ( @n0_Be3r )
- Attila Csatadi of ZeroDayBugs.com
- 71C4
- Nguyen Tai Phuc An of SACOMBANK
- Yudai Shibata
- Yudai Shibata
- Artur Stetsko
- Kevin Gosse
- Weeraphat Srisutham
- Jacob Keith with Keith Systems
- Grace Chapel
- Mika Vehns with MIVE GmbH
- Pocas (Jeongwon Jo)
- Mariusz Maik
- hsuan0223x
- Lucas Gabriel
- Edmilson Júnior (sierghart)
- alittleston3
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |