Patch tracker / KB5121000

KB5121000: Windows Server 2019 Security Update (August 2026)

KB5121000 is a Critical security update for Windows Server 2019, released 2026-08-11. It closes 196 CVEs with a maximum CVSS of 9.8. At least one of them is actively exploited (CISA KEV), so this is a deploy-first update. It is the third largest of the 70 updates Microsoft shipped that month, by CVEs closed.

Update summary

CriticalCISA KEV
Hot patch: #6 hottest Microsoft update right now, a must-install (as of 2026-08-11)
2026-08-11
Released
196
CVEs fixed
9.8
Max CVSS
Critical
Severity
Deploy now
This update fixes vulnerabilities confirmed exploited in the wild.

Fixes 196 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.8 (Critical). 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.

  • Microsoft is not currently aware of any issues with this update.

The full text, quoted from Microsoft

Microsoft Update Catalog: download KB5121000Microsoft support article
Senserva AI Opinion and rich prompt for KB5121000

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

Full tracking and change history for KB5121000

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 KB5121000 is installed

Elevated PowerShell. No output means it is not installed.

Known issues, from Microsoft

Quoted from Microsoft's support article for KB5121000 (checked 2026-08-11). Verify against the article before acting.

Microsoft is not currently aware of any issues with this update.

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-2026-56179Critical9.8-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-2026-61357Critical9.8-No
CVE-2026-61358Critical9.8-No
CVE-2026-61359Critical9.8-No
CVE-2026-61360Critical9.8-No
CVE-2026-61361Critical9.8-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-2026-61920Critical9.8-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-2026-61927Critical9.8-No
CVE-2026-61928Critical9.8-No
CVE-2026-61929Critical9.8-No
CVE-2026-61930Critical9.8-No
CVE-2026-61933Critical9.8-No
CVE-2026-61934Critical9.8-No
CVE-2026-61936Critical9.8-No
CVE-2026-61937Critical9.8-No
CVE-2026-61938Critical9.8-No
CVE-2026-61939Critical9.8-No
CVE-2026-62688Critical9.8-No
CVE-2026-62690Critical9.8-No
CVE-2026-62692Critical9.8-No
CVE-2026-62693Critical9.8-No
CVE-2026-62695Critical9.8-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-2026-62705Critical9.8-No
CVE-2026-62707Critical9.8-No
CVE-2026-62708Critical9.8-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-2026-62722Critical9.8-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-2026-62736Critical9.8-No
CVE-2026-62737Critical9.8-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-2026-62749Critical9.8-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-2026-62766Critical9.8-No
CVE-2026-62768Critical9.8-No
CVE-2026-62769Critical9.8-No
CVE-2026-62770Critical9.8-No
CVE-2026-62771Critical9.8-No
CVE-2026-62772Critical9.8-No
CVE-2026-62773Critical9.8-No
CVE-2026-62774Critical9.8-No
CVE-2026-62775Critical9.8-No
CVE-2026-62777Critical9.8-No
CVE-2026-62779Critical9.8-No
CVE-2026-62780Critical9.8-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-2026-62788Critical9.8-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-2026-62798Critical9.8-No
CVE-2026-62799Critical9.8-No
CVE-2026-62800Critical9.8-No
CVE-2026-62811Critical9.8-No
CVE-2026-62815Critical9.8-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-2026-65672Critical9.8-No
CVE-2026-65678Critical9.8-No
CVE-2026-65773Critical9.8-No
CVE-2026-65774Critical9.8-No
CVE-2026-65775Critical9.8-No
CVE-2026-65776Critical9.8-No
CVE-2026-65777Critical9.8-No
CVE-2026-65779Critical9.8-No
CVE-2026-65780Critical9.8-No
CVE-2026-65784Critical9.8-No
CVE-2026-65785Critical9.8-No
CVE-2026-65786Critical9.8-No
CVE-2026-65787Critical9.8-No
CVE-2026-65788Critical9.8-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-2026-66802Critical9.8-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
CVE-2026-70348Critical9.8-No
CVE-2026-72971Critical9.8-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 KB5121000 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.