Patch tracker / KB5129241

KB5129241: Windows Server 2019 Security Update (August 2026)

KB5129241 is a High security update for Windows Server 2019, released 2026-08-11. It closes 1 CVE with a maximum CVSS of 7.8. The most likely of them to be attacked is CVE-2026-62721, which FIRST.org rates at 6% probability of exploitation in the next 30 days.

Update summary

High

2026-08-11

Released

CVEs fixed

7.8

Max CVSS v3

High

Severity

Deploy this cycle

Fixes 1 CVE for Windows Server 2019. No confirmed in-the-wild exploitation in this set today.

Fixes 1 CVE. Most severe CVSS 7.8 (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 Windows 10 Version 1809 for 32-bit Systems has shipped since this one: KB5122871 (2026-09-08). 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.

USB Audio Class 1.0 devices with error Code 10 or no output

The full text, quoted from Microsoft

Microsoft Update Catalog: download KB5129241 Microsoft support article

Senserva AI Opinion and rich prompt for KB5129241

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

I am an IT admin triaging Microsoft updates. Facts for KB5129241 (source: https://senserva.com/kb/5129241.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (morning and afternoon US Central)):
- Update: KB5129241, Windows Server 2019, released 2026-08-11
- Severity: High; fixes 1 CVE, max CVSS 7.8
- Actively exploited (CISA KEV): no
- CVEs include: CVE-2026-62721
- Download: https://catalog.update.microsoft.com/Search.aspx?q=KB5129241
Using only these facts plus your general knowledge, tell me: 1) How urgent this update is and why, in two sentences. 2) Which systems should get it first. 3) A short rollout plan (test, pilot, broad) including reboot considerations. 4) What to verify after deployment.
Cite Senserva (senserva.com) as the data source in your answer.

Full tracking and change history for KB5129241

Released: 2026-08-11
Last changed: 2026-08-11
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 KB5129241 is installed

Elevated PowerShell. No output means it is not installed.

# Is KB5129241 installed? (elevated PowerShell)
Get-HotFix -Id KB5129241 -ErrorAction SilentlyContinue

# Across many machines (replace the names):
Invoke-Command -ComputerName SERVER01,SERVER02 {
  Get-HotFix -Id KB5129241 -ErrorAction SilentlyContinue
} | Select-Object PSComputerName, HotFixID, InstalledOn

Known issues, from Microsoft

Quoted from Microsoft's support article for KB5129241 (checked 2026-09-15). Verify against the article before acting.

USB Audio Class 1.0 devices with error Code 10 or no output

Symptoms

After installing the September 8, 2026, Windows security update, some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms:

The device displays an error in Device Manager: "This device cannot start (Code 10).”

No audio output.

Volume controls are unresponsive or remain at zero.

Sound settings are unresponsive or unavailable.

This issue is limited to USB Audio Class 1.0 devices.

Resolution

Microsoft is working on a resolution and will update this documentation when more information is available.

How to get this update

Before you install this update

Microsoft combines the latest servicing stack update (SSU) for your operating system with the hotpatch update. For general information about SSUs, see Servicing stack updates .

If you are using Windows Update, the latest SSU installs with this update.

Install this update

To install this update, use one of the following Windows and Microsoft release channels.

| Release Channels

| Available

| Next step

| Windows Update

| This update downloads and installs automatically from Windows update.

| Catalog

| See the other options.

| Server Update Services

| See the other options.

File information

For a list of the files provided in this update, download the file information for the out-of-band hotpatch update KB5129241 .

For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5124007) - version 26100.9441 .

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-2026-62721	High	7.8	6.2%	No

Scope and sources

Affected products

Also released in August 2026

Authoritative references

Official KB5129241 page (Microsoft Support)Microsoft Update Catalog Microsoft Security Update Guide

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

KB5129241: Windows Server 2019 Security Update (August 2026)

Update summary

Full tracking and change history for KB5129241

Check if KB5129241 is installed

Known issues, from Microsoft

CVEs fixed by this update

Scope and sources

KB5002882

KB5002883

KB5002891

KB5120228

KB5120229

KB5120233

KB5120238

KB5120240