Patch tracker / KB5087541

KB5087541: Windows Server 2022, 23H2 Edition Security Update (May 2026)

KB5087541 is a Critical security update for Windows Server 2022, 23H2 Edition, released 2026-05-12. It closes 58 CVEs with a maximum CVSS of 9.8. It is the sixth largest of the 65 updates Microsoft shipped that month, by CVEs closed.

Update summary

Critical
2026-05-12
Released
58
CVEs fixed
9.8
Max CVSS v3
Critical
Severity
Deploy this cycle
Fixes 58 CVEs for Windows Server 2022, 23H2 Edition. No confirmed in-the-wild exploitation in this set today.

Fixes 58 CVEs. Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 2.2%. Among the top half of tracked Microsoft updates by EPSS exploit probability.

Senserva found thisread these before you deploy broadly

Microsoft documents 1 known issue with this update.

  • Windows Server Update Services (WSUS) does not display error details

The full text, quoted from Microsoft

Microsoft Update Catalog: download KB5087541Microsoft support article
Senserva AI Opinion for KB5087541

KB5087541 is a large rollup for Windows 10 Version 1809 and Windows Server 2019, closing 58 CVEs including one rated Critical at CVSS 9.8 with an 80 percent EPSS score, meaning exploitation is statistically likely soon even though nothing here is in CISA KEV yet. The 1809 branch and Server 2019 fleets carry this, and the high EPSS on a remotely exploitable Critical flaw is the standout risk in this batch. No ransomware linkage is recorded so far, but the exploitation probability is high enough to treat as time sensitive.

Do this: Deploy KB5087541 to all Windows 10 1809 and Server 2019 systems now, prioritizing internet-facing and domain-joined servers.

AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for KB5087541

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

Full tracking and change history for KB5087541

Released
2026-05-12
Last changed
2026-09-26
Changes tracked
4

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 KB5087541 is installed

Elevated PowerShell. No output means it is not installed.

Known issues, from Microsoft

Quoted from Microsoft's support article for KB5087541 (checked 2026-08-06). Verify against the article before acting.

Windows Server Update Services (WSUS) does not display error details

After installing KB5070879 or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287 .

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-2025-54518High9.84.9%No
CVE-2026-41089Critical9.82.2%No
CVE-2026-41096Critical9.82.3%No
CVE-2026-34329High8.82.3%No
CVE-2026-40403High8.82.3%No
CVE-2026-40415High8.12.3%No
CVE-2026-33834High7.82.3%No
CVE-2026-33835High7.82.3%No
CVE-2026-33837High7.82.3%No
CVE-2026-33838High7.82.3%No
CVE-2026-33841High7.82.3%No
CVE-2026-34330High7.82.3%No
CVE-2026-34333High7.82.3%No
CVE-2026-34334High7.82.3%No
CVE-2026-34336High7.82.3%No
CVE-2026-34337High7.82.3%No
CVE-2026-34338High7.82.3%No
CVE-2026-34343High7.82.3%No
CVE-2026-34344High7.82.3%No
CVE-2026-34351High7.82.3%No
CVE-2026-35415High7.82.3%No
CVE-2026-35417High7.82.3%No
CVE-2026-35418High7.82.3%No
CVE-2026-35420High7.82.2%No
CVE-2026-35421High7.82.3%No
CVE-2026-40377High7.82.3%No
CVE-2026-40382High7.82.3%No
CVE-2026-40397High7.82.3%No
CVE-2026-40398High7.82.3%No
CVE-2026-40399High7.82.3%No
CVE-2026-40407High7.82.3%No
CVE-2026-40408High7.82.3%No
CVE-2026-41088High7.82.3%No
CVE-2026-41095High7.82.2%No
CVE-2026-32161High7.52.3%No
CVE-2026-35424High7.52.3%No
CVE-2026-40406High7.52.3%No
CVE-2026-40413High7.42.3%No
CVE-2026-40414High7.42.3%No
CVE-2026-40401High7.12.3%No
CVE-2026-33839High7.02.3%No
CVE-2026-34331High7.02.3%No
CVE-2026-34340High7.02.3%No
CVE-2026-34341High7.02.3%No
CVE-2026-34342High7.02.3%No
CVE-2026-34345High7.02.3%No
CVE-2026-34347High7.02.3%No
CVE-2026-35416High7.02.3%No
CVE-2026-40410High7.02.3%No
CVE-2026-42825High7.04.9%No
CVE-2026-21530Medium6.72.3%No
CVE-2026-32170Medium6.72.3%No
CVE-2026-41097Medium6.72.3%No
CVE-2026-35422Medium6.52.3%No
CVE-2026-40380Medium6.22.3%No
CVE-2026-34339Medium5.52.3%No
CVE-2026-35423Medium5.42.3%No
CVE-2026-32209Medium4.42.3%No

Scope and sources

Affected products
Also released in May 2026

KB5002863

9 CVEs · High · exploited

KB5002868

9 CVEs · High · exploited

KB5002870

9 CVEs · High · exploited

KB5094139

1 CVE · High · exploited

KB5094140

1 CVE · High · exploited

KB5094142

1 CVE · High · exploited

KB5094144

1 CVE · High · exploited

KB5078943

3 CVEs · Critical

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5087541 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.
All information provided as is, without warranty; verify against the vendor advisory before acting. All information and usage is subject to the Senserva EULA. Data notice and terms.