CVE-2026-96940
Microsoft Exchange Server Elevation of Privilege Vulnerability
No known exploitation. EPSS puts it in the 41st percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- Microsoft Exchange Server 2016 Cumulative Update 23Affected: ≥ 15.01.0.0, < 15.01.2507.075Upgrade to: 15.01.2507.075Stated by: CVE record
- Microsoft Exchange Server 2019 Cumulative Update 14Affected: ≥ 15.02.0.0, < 15.02.1544.048Upgrade to: 15.02.1544.048Stated by: CVE record
- Microsoft Exchange Server 2019 Cumulative Update 15Affected: ≥ 15.02.0.0, < 15.02.1748.053Upgrade to: 15.02.1748.053Stated by: CVE record
- Microsoft Exchange Server Subscription Edition RTMAffected: ≥ 15.02.0.0, < 15.02.2562.053Upgrade to: 15.02.2562.053Stated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
Coverage timeline
2 publishersMicrosoft released out-of-band updates for CVE-2026-96940, a high-severity weak authorization flaw in Exchange Server allowing authenticated attackers to read other users' mailboxes.
Sourced from public security reporting — each date is when it was published, not when it happened. 2 further articles named this CVE in wider roundups without reporting it as a distinct event.
What it is
From the CVE record
An elevation of privilege vulnerability exists when Microsoft Exchange Outlook Web Access (OWA) fails to properly handle web requests. An attacker who successfully exploited this vulnerability could perform script/content injection attacks and attempt to trick the user into disclosing sensitive information. To exploit the vulnerability, an attacker could send a specially crafted email message containing a malicious link to a user. Alternatively, an attacker could use a chat client to social engineer a user into clicking the malicious link. The security update addresses the vulnerability by correcting how Microsoft Exchange validates web requests. Note: In order to exploit this vulnerability, a user must click a maliciously crafted link from an attacker.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 41st percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
- Attention now
Sustained, driven by in-the-wild reports.
Lifecycle
7 events over 6 days, from the signal feeds we watch.
- Record updated
- Record updated
- Record updated
- Publishedweakness classified, record updated, record updated
Affected products
- Microsoft Exchange Server 2016 Cumulative Update 23Operating Systems
- Microsoft Exchange Server 2019 Cumulative Update 14Operating Systems / windows
- Microsoft Exchange Server 2019 Cumulative Update 15Enterprise Software / itsm-monitoring
- Microsoft Exchange Server Subscription Edition RTMEnterprise Software / itsm-monitoring
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 8.8 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
References in the record
In the news
- ⚡ Weekly Recap: Helpdesk 0-Days, Rogue Certs, ShinyHunters Arrest, AI-Fooling Malware and More
- Week in review: FortiBleed is still active, Patch Tuesday forecast
- Microsoft Exchange Flaw Lets Authenticated Attackers Read Other Users' Mailboxes
- Out-of-band Exchange Server update fixes high-severity mailbox access bug (CVE-2026-96940)
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