CVE-2026-54998

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

CVSS v3.1

8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.78% chance of exploitation in the next 30 days, 53th percentile

Published

2026-07-02

Updated

2026-08-31

Proof-of-concept exploits (1)

• sentinel-aidefense/CVE-2026-54998-exp3★ · 2026-07-04

References

• CVE Record
• NVD entry

Related

• CVE-2026-0163
• CVE-2026-56164
• CVE-2026-69836
• CVE-2026-54992
• CVE-2026-55040
• CVE-2026-54984