Jul 2026: Microsoft Exchange Server Elevation of Privilege Vulnerability
CVE-2026-55009 Published on July 14, 2026
Microsoft Exchange Server Elevation of Privilege Vulnerability
Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
Weakness Type
What is a Marshaling, Unmarshaling Vulnerability?
The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
CVE-2026-55009 has been classified to as a Marshaling, Unmarshaling vulnerability or weakness.
Products Associated with CVE-2026-55009
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Affected Versions
Microsoft Exchange Server 2016 Cumulative Update 23:- Version 15.01.0.0 and below 15.01.2507.071 is affected.
- Version 15.02.0.0 and below 15.02.1544.043 is affected.
- Version 15.02.0.0 and below 15.02.1748.048 is affected.
- Version 15.02.0.0 and below 15.02.2562.045 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.