CVE-2026-55009

EUVD-2026-44027
Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.8 HIGH
LOCAL
LOW
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 84.37%
Affected Products (NVD)
VendorProductVersion
microsoftexchange_server
𝑥
< 15.02.2562.045
microsoftexchange_server
15.1.0.0 ≤
𝑥
< 15.1.2507.71
microsoftexchange_server
15.2.0.0 ≤
𝑥
< 15.2.1544.43
microsoftexchange_server
15.2.0.0 ≤
𝑥
< 15.2.1748.48
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55009