CVE-2026-54998

⚠️ high

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

CVSS Score

8.8

High

EPSS Score

0.6

Exploit Probability

Published Date

2026-07-02

First Seen: 2026-07-03

This CVE is High Risk - more severe than 81.0% of all 340,405 vulnerabilities in our database.

#64,719

Top 25% most severe

Severity Percentile

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Total

Complete system compromise possible

SSVC data provided by CISA

Last Modified 2026-07-07

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE IDs (Weakness Types)

CWE-863

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
microsoft	exchange_online	Affected	v-

Vendor Advisory

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-56191	⛔ critical	10.0	0.7	Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network...	2026-07-24
CVE-2026-48582	⛔ critical	9.6	0.4	Missing authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.	2026-06-19
CVE-2026-48579	⛔ critical	9.1	1.0	Improper authorization in Microsoft Exchange Online allows an unauthorized attacker to disclose information over a netwo...	2026-06-04

These CVEs affect the same products