VDB-376012 · CVE-2026-54998 · GCVE-0-2026-54998

Microsoft Exchange Online authorization

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.6	$5k-$25k	2.86+

Summaryinfo

A vulnerability classified as very critical was found in Microsoft Exchange Online. Affected is an unknown function. Executing a manipulation can lead to authorization. This vulnerability is tracked as CVE-2026-54998. The attack can be launched remotely. No exploit exists. This product is a managed service. This means that users cannot maintain vulnerability countermeasures themselves.

Detailsinfo

A vulnerability classified as very critical was found in Microsoft Exchange Online (version unknown). This vulnerability affects an unknown function. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-863. 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. This allows attackers to bypass intended access restrictions. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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

The advisory is shared for download at msrc.microsoft.com. This vulnerability was named CVE-2026-54998 since 06/16/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/03/2026).

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Groupware Software

Vendor

Microsoft

Name

Exchange Online

License

commercial

Managed Service

Website

Vendor: https://www.microsoft.com/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.6

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authorization
CWE: CWE-863 / CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/16/2026 CVE reserved
07/03/2026 +17 days Advisory disclosed
07/03/2026 +0 days VulDB entry created
07/03/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-54998 (🔒)
GCVE (CVE): GCVE-0-2026-54998
GCVE (VulDB): GCVE-100-376012

Entryinfo

Created: 07/03/2026 06:19
Changes: 07/03/2026 06:19 (61)
Complete: 🔍
Cache ID: 216::103