High severity · published Oct 2, 2026
CVE-2026-96940
Microsoft Exchange Server Elevation of Privilege Vulnerability
8.8
CVSS
2.7%
EPSS
No
On KEV
Description
Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.7% · higher than 86% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ES
Exchange Server · Microsoft
2016; 2019; 2019 · source: NVD
ME
Microsoft Exchange Server 2016 Cumulative Update 23 · Microsoft
15.01.0.0 before 15.01.2507.075 · source: vendor
ME
Microsoft Exchange Server 2019 Cumulative Update 14 · Microsoft
15.02.0.0 before 15.02.1544.048 · source: vendor
ME
Microsoft Exchange Server 2019 Cumulative Update 15 · Microsoft
15.02.0.0 before 15.02.1748.053 · source: vendor
ME
Microsoft Exchange Server Subscription Edition RTM · Microsoft
15.02.0.0 before 15.02.2562.053 · source: vendor
ES
Exchange Server Subscription Edition · Microsoft
before 15.02.2562.053 · source: NVD
In the news
VulnerabilityHigh
CVE-2026-96940: Microsoft Fixes Exchange Server Flaw For Which Exploitation Is More Likely
Microsoft released emergency updates for Exchange Server to fix CVE-2026-96940, a high-severity flaw that can let attackers gain higher privileges. Microsoft has released out-of-band security updates for Exchange Server to fix a high-severity vulnerability tracked as CVE-2026-96940 (CVSS score of 8.8). The flaw is caused by weak authorization and can allow an authenticated attacker to […]
Oct 6, 2026·Security Affairs
VulnerabilityHigh
Microsoft Exchange Flaw Lets Authenticated Attackers Read Other Users' Mailboxes
Microsoft has released out-of-band security updates to address a high-severity flaw in Microsoft Exchange Server that could allow an attacker to escalate privileges under certain conditions. The vulnerability, tracked as CVE-2026-96940, is rated 8.8 on the CVSS scoring system. "Weak authorization in Microsoft Exchange Server allows an authenticated attacker to elevate privileges over a
Oct 5, 2026·The Hacker News
VulnerabilityHigh
Out-of-band Exchange Server update fixes high-severity mailbox access bug (CVE-2026-96940)
Microsoft has pushed out an out-of-band security update for Exchange Server that fixes a high-severity vulnerability (CVE-2026-96940) that may allow authenticated attackers to read emails and attachments of other users in the same organization, but “does not allow access across tenant boundaries.” CVE-2026-96940 was discovered internally and, according to the Exchange Server Team, they “are not aware of active exploitation.” Nevertheless, Microsoft thinks that the flaw could be consistently exploited and notes that this type … More → The post Out-of-band Exchange Server update fixes high-severity mailbox access bug (CVE-2026-96940) appeared first on Help Net Security .
Oct 5, 2026·Help Net Security
Affected product
ES
Exchange Server
Microsoft
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