Patch tracker / KB5066747
KB5066747: .NET 8.0 installed on Linux Security Update (October 2025)
KB5066747 is a Medium security update for .NET 8.0 installed on Linux, released 2025-10-14. It closes 1 CVE with a maximum CVSS of 4.8. The most likely of them to be attacked is CVE-2025-55248, which FIRST.org rates at 66% probability of exploitation in the next 30 days.
Update summary
Fixes 1 CVE. Most severe CVSS 4.8 (Medium). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for .NET 8.0 installed on Linux has shipped since this one: KB5077862 (2026-02-10). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.
KB5066747 patches CVE-2025-55248 in .NET 8.0 and .NET 9.0 running on Linux and macOS, so this affects your cross-platform .NET runtimes rather than Windows hosts. The severity is Medium at CVSS 4.8 with a 1 percent EPSS, and it is not in CISA KEV nor tied to ransomware, so this is a routine maintenance patch rather than an urgent fix. The unusual angle here is that the exposure lives on your Linux and Mac developer machines and servers, which are easy to overlook in a Windows-centric patch cycle.
Do this: Inventory Linux and macOS systems running .NET 8.0 or 9.0 and update their runtime packages to the versions carrying KB5066747.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5066747
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5066747
- Released
- 2025-10-14
- Last changed
- 2025-10-14
- Changes tracked
- 1
Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.
Check if KB5066747 is installed
Elevated PowerShell. No output means it is not installed.
CVEs fixed by this update
Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.
| CVE | Severity | CVSS | EPSS | Exploited |
|---|---|---|---|---|
| CVE-2025-55248 | Medium | 4.8 | 66% | No |
Scope and sources
- Affected products
- Also released in October 2025
KB5070879
1 CVE · Critical · exploitedKB5070881
1 CVE · Critical · exploitedKB5070882
1 CVE · Critical · exploitedKB5070883
1 CVE · Critical · exploitedKB5070884
1 CVE · Critical · exploitedKB5070886
1 CVE · Critical · exploitedKB5070887
1 CVE · Critical · exploitedKB5070892
1 CVE · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.