CVE-2026-21511

EUVD-2026-7331
Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
microsoftCNA
7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Base Score
CVSS 3.x
EPSS Score
Percentile: 32%
Affected Products (NVD)
VendorProductVersion
microsoft365_apps
-
microsoft365_apps
-
microsoftsharepoint_server
𝑥
< 16.0.19127.20518
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21511