PT-2026-55320 · Microsoft · Exchange Online

Stefan Weywith · Published 2026-07-02 · Updated 2026-07-03 · CVE-2026-54998

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Microsoft Exchange Online (affected versions not specified)

Description Incorrect authorization allows an authorized attacker to elevate privileges over a network.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

CVE-2026-54998

Affected Products

Exchange Online

References · 4

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-54998 · Security Note
• https://twitter.com/CVEnew/status/2072814560457920908 · Twitter Post
• https://twitter.com/vuldb/status/2072909348553330778 · Twitter Post