What is CVE-2026-55007?

CVE-2026-55007 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Microsoft Exchange Server Remote Code Execution Vulnerability

Which CVE IDs does CVE-2026-55007 cover?

CVE-2026-55007 covers the following CVE IDs: CVE-2026-55007. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-55007?

CVE-2026-55007 has a CVSS v3 base score of 8.1, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-55007?

CVE-2026-55007 affects 3 products, including: Microsoft Exchange Server 2019 Cumulative Update 14; Microsoft Exchange Server 2019 Cumulative Update 15; Microsoft Exchange Server Subscription Edition RTM.

CVE-2026-55007HighCVSS 8.1

Microsoft Exchange Server Remote Code Execution Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

September 11, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-55007 →

📋 Description

Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

🎯 Affected products3

Microsoft Exchange Server 2019 Cumulative Update 14
Microsoft Exchange Server 2019 Cumulative Update 15
Microsoft Exchange Server Subscription Edition RTM

✅ Remediation

KB5121610 (Security Update) — fixed build 15.02.1544.046 KB5121609 (Security Update) — fixed build 15.02.1748.051 KB5121608 (Security Update) — fixed build 15.02.2562.049

🔗 References (5)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007
referencehttps://support.microsoft.com/help/5121610
referencehttps://support.microsoft.com/help/5121609
patchhttps://www.microsoft.com/en-us/download/details.aspx?id=108825
referencehttps://support.microsoft.com/help/5121608