Patch tracker / KB5081277
KB5081277: ASP.NET Core 8.0 Security Update (March 2026)
KB5081277 is a High security update for ASP.NET Core 8.0, released 2026-03-10. It closes 1 CVE with a maximum CVSS of 7.5. Get it from the Microsoft Update Catalog below, and see where it sits against the rest of the month on the patch tracker.
Update summary
New to these terms? How the Microsoft patching tools fit together, this month's Patch Tuesday summary, and every update ranked by real-world risk.
Senserva AI Opinion for KB5081277
KB5081277 patches CVE-2026-26130, a High severity (CVSS 7.5) flaw affecting ASP.NET Core 8.0, 9.0, and 10.0. Anyone running web applications or APIs built on these runtimes is exposed, though the 3% EPSS and absence from the CISA KEV catalog suggest exploitation is not yet widespread. The breadth across three consecutive major versions is the notable part, so shops standardized on any one of them still need to act.
Do this: Inventory servers running ASP.NET Core 8.0, 9.0, or 10.0 and apply the KB5081277 runtime update, then restart affected app pools or services.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5081277
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5081277
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.
Exploitation and severity
Fixes 1 CVE. Most severe CVSS 7.5 (High). EPSS exploit probability up to 2.8%.
Among the lower half of tracked Microsoft updates by EPSS exploit probability.
What to do
Moderate priority: schedule it in your normal patch cycle. Senserva flags whether KB5081277 is missing on your devices.
Check if KB5081277 is installed
Copy-paste PowerShell: one machine, or your whole estate in one pass. No output means the update is not installed.
Get-HotFix covers Windows updates. Office, SharePoint, and Exchange server updates show under installed updates in Programs and Features, or check the Update Catalog history.
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-2026-26130 | High | 7.8 | 2.8% | No |
Affected products
Also released in March 2026
The highest-risk updates from the same release:
The full month, summarized: Microsoft Patch Tuesday.
Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.