CVE-2026-54998 HIGH

CVE-2026-54998: Microsoft Exchange Online Elevation of Privilege Vulnerability

Vendor Microsoft

Product Microsoft Exchange Online

Weakness CWE-863 · Incorrect authorization

Published July 2, 2026

Last update July 3, 2026

View on NVD All CVEs

CVSS base score

8.8/10

Attack vector Network

Attack complexity Low

Privileges required Low

User interaction None

Confidentiality High

Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

July 2, 2026 CVE published

July 3, 2026 Record updated

External resources

03References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2026-54998 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/863.html AskarLabs — CWE-863 write-up Incorrect Authorization

Related vulnerabilities

04Related CVE

CVE-2026-54397 MISP event editing allows unauthorized assignment to undisclosed sharing groups CVE-2026-47236 Solidtime team page exposes pending invitation and member emails to employees who lack invitations:view/members:view permission CVE-2026-32966 Apache DolphinScheduler: DataSource API Missing Authorization Check Leads to Arbitrary Data Source Metadata Disclosure CVE-2026-48507 Snipe-IT: Bulk editing users allowed `ldap_import` and `activated_in` bulk editing users CVE-2026-53738 Copy & Delete Posts through 1.5.4 Privilege Escalation via cdp_action_handling Handler