Patch tracker / CVE reference / CVE-2025-26646

CVE-2025-26646

CVE-2025-26646 is a high severity Microsoft vulnerability with a CVSS score of 8.0. Microsoft has shipped the fix: deploy one of the 2 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High

8.0

CVSS

1.1%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 1.1%. CVSS 8.0 (High).

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

Senserva AI Opinion for CVE-2025-26646

A spoofing vulnerability in .NET 8.0 and Visual Studio build tooling, High Severity at CVSS 8.0, and unusually it spans Windows, Linux, and macOS installs of the runtime. Spoofing in the build toolchain points at supply-chain style abuse: forged packages or build artifacts that developers and CI systems accept as authentic. EPSS is only 1 percent, so treat it as toolchain hygiene rather than incident response.

Do this: Update .NET 8.0 SDKs and runtimes across all three operating systems in your build farm and developer machines during the next tooling refresh.

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

Senserva AI Opinion and rich prompt for CVE-2025-26646

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-2025-26646 (source: https://senserva.com/cve/CVE-2025-26646.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2025-26646: High severity Microsoft vulnerability, CVSS 8.0
- EPSS 30-day exploitation probability: 1.1%
- Actively exploited (CISA KEV): no
- Fixed by: KB5059200, KB5059201
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 1%.

Fixed by KB5059200 and 1 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-2025-26646

Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing updates KB5059200, KB5059201 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-2025-26646. 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.

KB5059200 KB5059201

Scope and sources

Affected products

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.