Patch tracker / KB5120249

KB5120249: Windows Server 2019 Security Update (August 2026)

KB5120249 is a High security update for Windows Server 2019, released 2026-08-11. It closes 159 CVEs with a maximum CVSS of 8.8. At least one of them is actively exploited (CISA KEV), so this is a deploy-first update. It is the 11th largest of the 70 updates Microsoft shipped that month, by CVEs closed.

Update summary

HighCISA KEV
2026-08-11
Released
159
CVEs fixed
8.8
Max CVSS
High
Severity
Deploy now
This update fixes vulnerabilities confirmed exploited in the wild.

Fixes 159 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 8.8 (High). This update fixes an actively-exploited (CISA KEV) vulnerability.

Senserva found thisread these before you deploy broadly

Microsoft documents 1 known issue with this update.

  • We are currently not aware of any issues with this update

The full text, quoted from Microsoft

Microsoft Update Catalog: download KB5120249Microsoft support article
Senserva AI Opinion and rich prompt for KB5120249

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

Full tracking and change history for KB5120249

Released
2026-08-11
Last changed
2026-08-11
Changes tracked
2

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 KB5120249 is installed

Elevated PowerShell. No output means it is not installed.

Known issues, from Microsoft

Quoted from Microsoft's support article for KB5120249 (checked 2026-08-11). Verify against the article before acting.

We are currently not aware of any issues with this update

Applies to: Windows 10 Enterprise LTSC 2021 and Windows 10 IoT Enterprise LTSC 2021

Important Use EKB KB5003791 to update to Windows 10, version 21H2 on supported editions.

This security update includes fixes and quality improvements that are part of the following updates:

July 14, 2026—KB5099539 (OS Builds 19045.7548 and 19044.7548)

The following is a summary of the issues that this update addresses when you install this update. If there are new features, it lists them as well. The bold text within the brackets indicates the item or area of the change we are documenting.

[Backup] File History automatic backups to network shares using Server Message Block (SMB) might fail with an incorrect "invalid credentials" error. When this issue occurs, scheduled backups do not copy any files. This update resolves the issue.

[Secure Boot] This update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Certificate deployment via Windows updates continues across supported PCs and non-managed business devices in the coming months.

If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.

For more information about security vulnerabilities, please refer to the new ...

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.

CVESeverityCVSSEPSSExploited
CVE-2026-68820Critical9.8-KEV
CVE-2026-49179Critical9.8-No
CVE-2026-50472Critical9.8-No
CVE-2026-54113Critical9.8-No
CVE-2026-54984Critical9.8-No
CVE-2026-56174Critical9.8-No
CVE-2026-59122Critical9.8-No
CVE-2026-59125Critical9.8-No
CVE-2026-59126Critical9.8-No
CVE-2026-59127Critical9.8-No
CVE-2026-59128Critical9.8-No
CVE-2026-59130Critical9.8-No
CVE-2026-59131Critical9.8-No
CVE-2026-59132Critical9.8-No
CVE-2026-59134Critical9.8-No
CVE-2026-59135Critical9.8-No
CVE-2026-59136Critical9.8-No
CVE-2026-59137Critical9.8-No
CVE-2026-59138Critical9.8-No
CVE-2026-61345Critical9.8-No
CVE-2026-61346Critical9.8-No
CVE-2026-61347Critical9.8-No
CVE-2026-61348Critical9.8-No
CVE-2026-61349Critical9.8-No
CVE-2026-61350Critical9.8-No
CVE-2026-61352Critical9.8-No
CVE-2026-61353Critical9.8-No
CVE-2026-61355Critical9.8-No
CVE-2026-61356Critical9.8-No
CVE-2026-61358Critical9.8-No
CVE-2026-61360Critical9.8-No
CVE-2026-61363Critical9.8-No
CVE-2026-61364Critical9.8-No
CVE-2026-61365Critical9.8-No
CVE-2026-61366Critical9.8-No
CVE-2026-61367Critical9.8-No
CVE-2026-61368Critical9.8-No
CVE-2026-61918Critical9.8-No
CVE-2026-61921Critical9.8-No
CVE-2026-61923Critical9.8-No
CVE-2026-61924Critical9.8-No
CVE-2026-61925Critical9.8-No
CVE-2026-61926Critical9.8-No
CVE-2026-61928Critical9.8-No
CVE-2026-61930Critical9.8-No
CVE-2026-61932Critical9.8-No
CVE-2026-61936Critical9.8-No
CVE-2026-61937Critical9.8-No
CVE-2026-61939Critical9.8-No
CVE-2026-62690Critical9.8-No
CVE-2026-62692Critical9.8-No
CVE-2026-62696Critical9.8-No
CVE-2026-62698Critical9.8-No
CVE-2026-62699Critical9.8-No
CVE-2026-62700Critical9.8-No
CVE-2026-62701Critical9.8-No
CVE-2026-62702Critical9.8-No
CVE-2026-62703Critical9.8-No
CVE-2026-62707Critical9.8-No
CVE-2026-62709Critical9.8-No
CVE-2026-62710Critical9.8-No
CVE-2026-62711Critical9.8-No
CVE-2026-62712Critical9.8-No
CVE-2026-62713Critical9.8-No
CVE-2026-62717Critical9.8-No
CVE-2026-62719Critical9.8-No
CVE-2026-62721Critical9.8-No
CVE-2026-62723Critical9.8-No
CVE-2026-62724Critical9.8-No
CVE-2026-62725Critical9.8-No
CVE-2026-62726Critical9.8-No
CVE-2026-62728Critical9.8-No
CVE-2026-62729Critical9.8-No
CVE-2026-62730Critical9.8-No
CVE-2026-62732Critical9.8-No
CVE-2026-62733Critical9.8-No
CVE-2026-62734Critical9.8-No
CVE-2026-62735Critical9.8-No
CVE-2026-62738Critical9.8-No
CVE-2026-62739Critical9.8-No
CVE-2026-62740Critical9.8-No
CVE-2026-62741Critical9.8-No
CVE-2026-62743Critical9.8-No
CVE-2026-62746Critical9.8-No
CVE-2026-62747Critical9.8-No
CVE-2026-62748Critical9.8-No
CVE-2026-62750Critical9.8-No
CVE-2026-62751Critical9.8-No
CVE-2026-62752Critical9.8-No
CVE-2026-62753Critical9.8-No
CVE-2026-62754Critical9.8-No
CVE-2026-62755Critical9.8-No
CVE-2026-62757Critical9.8-No
CVE-2026-62758Critical9.8-No
CVE-2026-62768Critical9.8-No
CVE-2026-62769Critical9.8-No
CVE-2026-62770Critical9.8-No
CVE-2026-62771Critical9.8-No
CVE-2026-62773Critical9.8-No
CVE-2026-62774Critical9.8-No
CVE-2026-62777Critical9.8-No
CVE-2026-62781Critical9.8-No
CVE-2026-62782Critical9.8-No
CVE-2026-62783Critical9.8-No
CVE-2026-62784Critical9.8-No
CVE-2026-62785Critical9.8-No
CVE-2026-62786Critical9.8-No
CVE-2026-62790Critical9.8-No
CVE-2026-62792Critical9.8-No
CVE-2026-62793Critical9.8-No
CVE-2026-62795Critical9.8-No
CVE-2026-62796Critical9.8-No
CVE-2026-62797Critical9.8-No
CVE-2026-62800Critical9.8-No
CVE-2026-62816Critical9.8-No
CVE-2026-62817Critical9.8-No
CVE-2026-62819Critical9.8-No
CVE-2026-62822Critical9.8-No
CVE-2026-62832Critical9.8-No
CVE-2026-62876Critical9.8-No
CVE-2026-62877Critical9.8-No
CVE-2026-62880Critical9.8-No
CVE-2026-62881Critical9.8-No
CVE-2026-62883Critical9.8-No
CVE-2026-62885Critical9.8-No
CVE-2026-62887Critical9.8-No
CVE-2026-62888Critical9.8-No
CVE-2026-62889Critical9.8-No
CVE-2026-62890Critical9.8-No
CVE-2026-62892Critical9.8-No
CVE-2026-62894Critical9.8-No
CVE-2026-62908Critical9.8-No
CVE-2026-65662Critical9.8-No
CVE-2026-65671Critical9.8-No
CVE-2026-65678Critical9.8-No
CVE-2026-65773Critical9.8-No
CVE-2026-65774Critical9.8-No
CVE-2026-65775Critical9.8-No
CVE-2026-65784Critical9.8-No
CVE-2026-65786Critical9.8-No
CVE-2026-65787Critical9.8-No
CVE-2026-65790Critical9.8-No
CVE-2026-65794Critical9.8-No
CVE-2026-65795Critical9.8-No
CVE-2026-65797Critical9.8-No
CVE-2026-65798Critical9.8-No
CVE-2026-65799Critical9.8-No
CVE-2026-65814Critical9.8-No
CVE-2026-66799Critical9.8-No
CVE-2026-66804Critical9.8-No
CVE-2026-6726Critical9.8-No
CVE-2026-6727Critical9.8-No
CVE-2026-70304Critical9.8-No
CVE-2026-70307Critical9.8-No
CVE-2026-70330Critical9.8-No
CVE-2026-70344Critical9.8-No
CVE-2026-70345Critical9.8-No
CVE-2026-70346Critical9.8-No
CVE-2026-70347Critical9.8-No

What the press says about this update

Trusted-source coverage of the CVEs this update fixes, pulled live from their own feeds.

“Patch Tuesday - August 2026” Rapid7, 2026-08-11
“Microsoft's August 2026 Patch Tuesday Addresses 398 CVEs (CVE-2026-68820)” Tenable, 2026-08-11
“The August 2026 Security Update Review” Zero Day Initiative, 2026-08-11

Scope and sources

Affected products
Also released in August 2026

KB5002882

39 CVEs · Critical · exploited

KB5002883

40 CVEs · Critical · exploited

KB5002891

40 CVEs · Critical · exploited

KB5120228

212 CVEs · Critical · exploited

KB5120229

194 CVEs · Critical · exploited

KB5120233

213 CVEs · Critical · exploited

KB5120238

181 CVEs · Critical · exploited

KB5120240

170 CVEs · Critical · exploited

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5120249 page (Microsoft Support)Microsoft Update CatalogMicrosoft Security Update Guide

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

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
Provided as is, without warranty; verify against the vendor advisory before acting. Data notice and terms.