# CVE-2026-109476: ASP.NET Core Information Disclosure Vulnerability

CVE-2026-109476 is fixed in 9 products on 1 platform, first by KB5135241, released November 10, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-109476
- Priority: Routine
- CVSS: 6.1 (Important)
- EPSS: 0.0064
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Nov 10, 2026
- Weakness: Improper Encoding or Escaping of Output
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109476

## Description

<p>Improper encoding or escaping of output in ASP.NET Core allows an unauthorized attacker to disclose information over a network.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | .NET 10.0 installed on Linux |  | [KB5135241](https://patchblox.com/security/data/fix/microsoft/kb5135241.md) | Nov 10, 2026 |
| Microsoft | .NET 10.0 installed on Mac OS |  | [KB5135241](https://patchblox.com/security/data/fix/microsoft/kb5135241.md) | Nov 10, 2026 |
| Microsoft | .NET 10.0 installed on Windows |  | [KB5135241](https://patchblox.com/security/data/fix/microsoft/kb5135241.md) | Nov 10, 2026 |
| Microsoft | .NET 8.0 installed on Linux |  | [KB5135243](https://patchblox.com/security/data/fix/microsoft/kb5135243.md) | Nov 10, 2026 |
| Microsoft | .NET 8.0 installed on Mac OS |  | [KB5135243](https://patchblox.com/security/data/fix/microsoft/kb5135243.md) | Nov 10, 2026 |
| Microsoft | .NET 8.0 installed on Windows |  | [KB5135243](https://patchblox.com/security/data/fix/microsoft/kb5135243.md) | Nov 10, 2026 |
| Microsoft | .NET 9.0 installed on Linux |  | [KB5135242](https://patchblox.com/security/data/fix/microsoft/kb5135242.md) | Nov 10, 2026 |
| Microsoft | .NET 9.0 installed on Mac OS |  | [KB5135242](https://patchblox.com/security/data/fix/microsoft/kb5135242.md) | Nov 10, 2026 |
| Microsoft | .NET 9.0 installed on Windows |  | [KB5135242](https://patchblox.com/security/data/fix/microsoft/kb5135242.md) | Nov 10, 2026 |

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Data as of 2026-11-11T13:47:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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