CVE-2026-54998CriticalMicrosoft CVSS 8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Microsoft advisory for CVE-2026-54998 — Microsoft Exchange Online

Published
July 7, 2026
Last Modified
—

🔗 CVE IDs covered (1)

CVE-2026-54998 →

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998. This page also shows what EchelonGraph holds for CVE-2026-54998, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products1

  • Microsoft Exchange Online

🧭 EchelonGraph on CVE-2026-54998

EchelonGraph score
8.8 HIGH
CISA KEV
Not listed
Fix status
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

Description from the CVE record (CVE.org), as published by its numbering authority

Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.

Published by Microsoft Corporation, the CVE Numbering Authority that assigned CVE-2026-54998, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (1)