Patch tracker / KB5100989
KB5100989: .NET 8.0 installed on Mac OS Security Update (July 2026)
KB5100989 is a High security update for .NET 8.0 installed on Mac OS, released 2026-07-14. It closes 17 CVEs with a maximum CVSS of 8.1. The most likely of them to be attacked is CVE-2026-47302, which FIRST.org rates at 64% probability of exploitation in the next 30 days.
Update summary
Fixes 17 CVEs. Most severe CVSS 8.1 (High). EPSS exploit probability up to 1.1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.
Microsoft documents 1 known issue with this update.
- Microsoft is not currently aware of any issues in this update.
KB5100989 is a Security Update bundling the .NET Framework 3.5 and 4.7.2 components on Windows 10 Version 1809 (32-bit, ARM64, x64) and Windows Server 2019. Anyone still running the older 1809 and Server 2019 baseline is exposed, and note that Microsoft has not yet published the per-update CVE detail for this July 2026 cycle, so the specific fixes remain provisional from the MSRC release document only. The release maps no named zero-days here, but it sits inside a large 622 CVE cycle with 56 rated Critical.
Do this: Stage KB5100989 on a 1809 or Server 2019 test box, confirm both the 3.5 and 4.7.2 legs apply cleanly, then deploy across your remaining 1809 and Server 2019 fleet.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5100989
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5100989
- Released
- 2026-07-14
- Last changed
- 2026-07-24
- Changes tracked
- 2
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 KB5100989 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5100989 (checked 2026-08-12). Verify against the article before acting.
Microsoft is not currently aware of any issues in this update.
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-2026-47304 | High | 8.1 | 64% | No |
| CVE-2026-50646 | High | 7.8 | 64% | No |
| CVE-2026-50649 | High | 7.8 | 64% | No |
| CVE-2026-50650 | High | 7.8 | 64% | No |
| CVE-2026-47302 | High | 7.5 | 64% | No |
| CVE-2026-50304 | High | 7.5 | 64% | No |
| CVE-2026-50355 | High | 7.5 | 64% | No |
| CVE-2026-50368 | High | 7.5 | 64% | No |
| CVE-2026-50411 | High | 7.5 | 64% | No |
| CVE-2026-50525 | High | 7.5 | 64% | No |
| CVE-2026-50527 | High | 7.5 | 64% | No |
| CVE-2026-50647 | High | 7.5 | 64% | No |
| CVE-2026-50648 | High | 7.5 | 64% | No |
| CVE-2026-50652 | High | 7.5 | 64% | No |
| CVE-2026-50653 | High | 7.5 | 64% | No |
| CVE-2026-50659 | Medium | 6.5 | 64% | No |
| CVE-2026-50324 | Medium | 5.9 | 64% | No |
Scope and sources
- Affected products
- Also released in July 2026
KB5099444
185 CVEs · Critical · exploitedKB5099445
174 CVEs · Critical · exploitedKB5099535
261 CVEs · Critical · exploitedKB5099536
389 CVEs · Critical · exploitedKB5099538
312 CVEs · Critical · exploitedKB5099539
314 CVEs · Critical · exploitedKB5099540
326 CVEs · Critical · exploitedKB5101649
383 CVEs · 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.