High severity · published Jun 4, 2026
CVE-2026-48579
Microsoft Exchange Online Information Disclosure Vulnerability
7.5
CVSS
1%
EPSS
No
On KEV
Description
Improper authorization in Microsoft Exchange Online allows an unauthorized attacker to disclose information over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 63% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ME
Microsoft Exchange Online · Microsoft
All versions, or not specified · source: vendor
EO
Exchange Online · Microsoft
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48579
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48579
Vendor Advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-48579
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