Microsoft Exchange Online improper 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 (≈)
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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.
8.2$25k-$100k3.84

Summaryinfo

A vulnerability was found in Microsoft Exchange Online. It has been rated as critical. Impacted is an unknown function. The manipulation leads to improper authorization. This vulnerability is uniquely identified as CVE-2026-48579. The attack is possible to be carried out remotely. No exploit exists. This product is a managed service, which means users themselves cannot handle vulnerability countermeasures.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Microsoft Exchange Online (version unknown). This issue affects an unknown function. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Improper authorization in Microsoft Exchange Online allows an unauthorized attacker to disclose information over a network.

The advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-48579 since 05/21/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $25k-$100k at the moment (estimation calculated on 06/05/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

This product is available as a managed service. Users are not able to maintain vulnerability countermeasures themselves.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-34338). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

License

Managed Service

  • yes

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 8.2

VulDB Base Score: 7.3
VulDB Temp Score: 7.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.1
CNA Vector (microsoft): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authorization
CWE: CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/21/2026 CVE reserved
06/04/2026 +14 days VulDB entry created
06/05/2026 +0 days Advisory disclosed
06/05/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-48579 (🔒)
GCVE (CVE): GCVE-0-2026-48579
GCVE (VulDB): GCVE-100-368417
EUVD: 🔒

Entryinfo

Created: 06/05/2026 00:52
Updated: 06/05/2026 04:12
Changes: 06/05/2026 00:52 (62), 06/05/2026 04:12 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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