# KB5077863: February 2026 security update

KB5077863, released February 10, 2026, fixes 1 CVE across 3 products. None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/microsoft/kb5077863
- Platform: Microsoft
- Released: Feb 10, 2026
- Priority: High (Closes CVE-2026-21218, high severity)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/5077863

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [.NET 8.0 runtime installed on Linux](https://patchblox.com/security/data/product/microsoft/net-8.0-runtime-installed-on-linux.md) |  |  |
| [.NET 8.0 runtime installed on Mac OS](https://patchblox.com/security/data/product/microsoft/net-8.0-runtime-installed-on-mac-os.md) |  |  |
| [.NET 8.0 runtime installed on Windows](https://patchblox.com/security/data/product/microsoft/net-8.0-runtime-installed-on-windows.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-21218](https://patchblox.com/security/data/cve/CVE-2026-21218.md) | High | .NET | 7.5 | 0.0100 |  |

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Data as of 2026-11-07T06:34:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo