Patch tracker / CVE reference / CVE-2026-45591

CVE-2026-45591

CVE-2026-45591 is a high severity Microsoft vulnerability with a CVSS score of 7.5. Microsoft has shipped the fix: deploy one of the 3 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High

7.5

CVSS

2.4%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 2.4%. CVSS 7.5 (High).

This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2026-45591

A denial of service flaw in ASP.NET Core that ships through Visual Studio 2026 version 18.6 and the .NET 10.0 runtime on Windows and macOS, rated High Severity at CVSS 7.8. The exposure is any internet-facing ASP.NET Core application on an unpatched .NET 10 runtime, which an attacker can knock over with crafted requests. Exploit probability is only 2 percent, so schedule it with your normal runtime update wave.

Do this: Update the .NET 10.0 runtime on your web application hosts and refresh Visual Studio 2026 on developer machines.

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

Senserva AI Opinion and rich prompt for CVE-2026-45591

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

I am an IT admin assessing a vulnerability. Facts for CVE-2026-45591 (source: https://senserva.com/cve/CVE-2026-45591.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-45591: High severity Microsoft vulnerability, CVSS 7.5
- EPSS 30-day exploitation probability: 2.4%
- Actively exploited (CISA KEV): no
- Fixed by: KB5097148, KB5097149, KB5097150
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) What to patch or mitigate first. 4) How to check whether my devices are exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Schedule normally

No exploitation observed: not in the CISA KEV catalog, EPSS 2%.

Fixed by KB5097148 and 2 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.

Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Official patch(es) for CVE-2026-45591

Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing updates KB5097148, KB5097149, KB5097150 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security updates below to fix CVE-2026-45591. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.

KB5097148 KB5097149 KB5097150

Scope and sources

Affected products

Fixed by the same updates

CVE-2026-45490 CVE-2026-45491

Authoritative references

Official CVE record (cve.org)NVD detail Microsoft MSRC FIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.