Patch tracker / KB5087053

KB5087053: .NET 8.0 installed on Windows Security Update (May 2026)

KB5087053 is a High security update for .NET 8.0 installed on Windows, released 2026-05-12. It closes 2 CVEs with a maximum CVSS of 7.3. It is the 21st largest of the 61 updates Microsoft shipped that month, by CVEs closed.

Update summary

High
2026-05-12
Released
2
CVEs fixed
7.3
Max CVSS v3
High
Severity
Deploy this cycle
Fixes 2 CVEs for .NET 8.0 installed on Windows. No confirmed in-the-wild exploitation in this set today.

Fixes 2 CVEs. Most severe CVSS 7.3 (High). EPSS exploit probability up to <1%. Among the lower half of tracked Microsoft updates by EPSS exploit probability.

Senserva found thiswe track every release for this product line, so we can tell you this package is behind

A newer security update for .NET 10.0 installed on Windows has shipped since this one: KB5100984 (2026-07-14). 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.

Senserva found thisread these before you deploy broadly

Microsoft documents 1 known issue with this update.

  • Microsoft is not currently aware of any issues in this update.

The full text, quoted from Microsoft

Senserva AI Opinion for KB5087053

KB5087053 patches two CVEs across .NET 8.0, 9.0, and 10.0 on Windows, with the more serious rated High at CVSS 7.3. Anyone running .NET applications or hosting .NET workloads on these runtime versions is exposed, though EPSS sits at only 1% and neither CVE is in CISA KEV or linked to ransomware. The spread across three supported .NET generations means most Windows estates with .NET installed will need this rather than a niche subset.

Do this: Inventory which .NET 8.0, 9.0, and 10.0 runtimes and SDKs are installed on your Windows servers and workstations, then deploy KB5087053 to those hosts.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for KB5087053

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Full tracking and change history for KB5087053

Released
2026-05-12
Last changed
2026-05-12
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 KB5087053 is installed

Elevated PowerShell. No output means it is not installed.

Known issues, from Microsoft

Quoted from Microsoft's support article for KB5087053 (checked 2026-08-07). 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.

CVESeverityCVSSEPSSExploited
CVE-2026-32177High7.32.4%No
CVE-2026-35433High7.32.4%No

See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
Provided as is, without warranty; verify against the vendor advisory before acting. Data notice and terms.