CVE-2026-114157: ASP.NET Core Security Feature Bypass Vulnerability
CVE-2026-114157 is an elevation of privilege vulnerability in ASP.NET Core, rated Important by Microsoft, with a CVSS 3.1 base score of 7.5 (High). An attacker can exploit it by an attacker with local access, with low privileges and without user interaction. 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 7 products in 1 product family (Developer Tools).
Key facts
- CVE ID
- CVE-2026-114157
- Severity
- High CVSS 7.5
- 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
- Developer Tools
CVSS score and vector
Microsoft scores CVE-2026-114157 at 7.5 (temporal 6.5) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | High |
| Privileges required | Low |
| User interaction | None |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | None |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in ASP.NET Core allows an authorized attacker to elevate privileges locally.
Frequently asked questions (Microsoft)
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to win a race condition.
What kind of security feature could be bypassed by successfully exploiting this vulnerability?
An attacker with access to a local Windows account could bypass the isolation intended to restrict an affected ASP.NET Core service to its own account. Successful exploitation could allow the attacker to access data or perform operations exposed by that service without the intended authorization.
Affected products (7)
Developer Tools
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| .NET 8.0 installed on Windows | KB5135243 | Security Update | 8.0.34 | |
| .NET 9.0 installed on Windows | KB5135242 | Security Update | 9.0.23 | |
| .NET 10.0 installed on Windows | KB5135241 | Security Update | 10.0.15 | |
| .NET 11.0 installed on Windows | 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
- Antonio Alonso-Stepanov
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |