Intel

CVE-2026-54998

exchange_online: Incorrect Authorization (CVE-2026-54998)

highPoCEPSS 0.8%

Description

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

Source: BSI CSAFBSI WID Portalcvelistv5NVD (NIST)Microsoft Security Update Guide

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

microsoftexchange_online

Metrics

XIEM Effective CVSS
8.8
Source: nvd-v3
EPSS percentile
54.5 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
—
Show all metrics
Severity
high
Priority score
89.06
Exploit maturity
PoC (publicly reported)
CVSS v3
8.8
EPSS score
0.8 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-07-02 22:18 UTC
CWE
CWE-863

Weakness classes (CWE)

  • CWE-863Class

    Incorrect Authorization

    The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

    cwe.mitre.org →

References & sources

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-07-07 05:16 UTC· 134c704f-9b21-4f2e-91b3-4a467353bcc0
    • SSVC: {"id":"CVE-2026-54998","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalI… → {"id":"CVE-2026-54998","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalI…
  2. Initial Analysis2026-07-06 18:58 UTC· nvd@nist.gov
    • CPE Configuration: OR *cpe:2.3:a:microsoft:exchange_online:-:*:*:*:*:*:*:*
    • Reference Type: Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998 Types: Vendor Advisory
  3. CVE Modified2026-07-06 17:16 UTC· 134c704f-9b21-4f2e-91b3-4a467353bcc0
    • SSVC: {"id":"CVE-2026-54998","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalI…
  4. New CVE Received2026-07-02 23:16 UTC· secure@microsoft.com
    • Affected: Microsoft Exchange Online
    • Tag: exclusively-hosted-service
    • Description: Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
    • CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Linked advisories