Patch tracker / KB5050673

KB5050673: Microsoft Exchange Server Subscription Security Update (August 2025)

KB5050673 is a High security update for Microsoft Exchange Server Subscription, released 2025-08-12. It closes 1 CVE with a maximum CVSS of 8.0. The most likely of them to be attacked is CVE-2025-53786, which FIRST.org rates at 7% probability of exploitation in the next 30 days.

Update summary

High
2025-08-12
Released
1
CVEs fixed
8.0
Max CVSS v3
High
Severity
Deploy this cycle
Fixes 1 CVE for Microsoft Exchange Server Subscription. No confirmed in-the-wild exploitation in this set today.

Fixes 1 CVE. Most severe CVSS 8.0 (High). EPSS exploit probability up to 7.4%. Among the top 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 Microsoft Exchange Server Subscription Edition RTM has shipped since this one: KB5121573 (2026-08-11). 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.

Microsoft Update Catalog: download KB5050673Microsoft support article
Senserva AI Opinion for KB5050673

KB5050673 addresses CVE-2025-53786, a High severity flaw (CVSS 8.0) affecting Microsoft Exchange Server Subscription Edition, Exchange 2019 CU15, and Exchange 2016 CU23. This one matters for hybrid Exchange deployments where the on-premises server and Exchange Online share a trust relationship, since that connection is the exposure path. It is not in CISA KEV and not ransomware-linked, with a modest 7 percent EPSS, but the hybrid attack surface makes it worth prioritizing over a routine patch.

Do this: Apply KB5050673 to your on-premises Exchange servers and follow Microsoft's hybrid configuration hardening guidance for the Exchange to Exchange Online trust.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for KB5050673

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

Full tracking and change history for KB5050673

Released
2025-08-12
Last changed
2025-08-12
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 KB5050673 is installed

Elevated PowerShell. No output means it is not installed.

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-2025-53786High8.07.4%No

Scope and sources

Affected products
Also released in August 2025

KB5058379

36 CVEs · High · exploited

KB5058383

39 CVEs · High · exploited

KB5058384

44 CVEs · High · exploited

KB5058385

42 CVEs · High · exploited

KB5058387

33 CVEs · High · exploited

KB5058392

42 CVEs · High · exploited

KB5058405

38 CVEs · High · exploited

KB5058411

44 CVEs · High · exploited

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5050673 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.