Microsoft Exchange Online
CVE-2026-54998 — Microsoft Exchange Online Elevation of Privilege Vulnerability
Executive Summary
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
Overview
8.8
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
N/A
MS Exploit Likelihood
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
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.7
EPSS Score
0.00648
probability of exploitation in the next 30 days
0.47958 percentile - updated 2026-08-14
View on FIRST.org
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
References
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