Patch tracker / KB5066739

KB5066739

Microsoft security update released 2025-10-14. Fixes 1 CVE.

Medium

Download KB5066739

Get the official update for KB5066739. The download and file size for each supported product are on the Microsoft Update Catalog page.

Microsoft Update Catalog: download KB5066739 Microsoft support article

Update summary

Released

2025-10-14

CVEs fixed

1

Max CVSS

4.8

Severity

Medium

Exploitation and severity

Fixes 1 CVE. Most severe CVSS 4.8 (Medium). EPSS exploit probability up to <1%.

Among the lower half of tracked Microsoft updates by EPSS exploit probability.

What to do

Lower priority: patch in your normal cycle. Senserva flags whether KB5066739 is missing on your devices.

CVEs fixed by this update

Affected products

.NET 8.0 installed on Linux
.NET 8.0 installed on Mac OS
.NET 9.0 installed on Linux

References

Microsoft support article Microsoft Security Update Guide

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

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Lexicon: the terms on this page

CVE: Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB: Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV: CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS: Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS: Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC: Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD: National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware: The vulnerability is linked to known ransomware activity.