CVE-2026-21258

EUVD-2026-7356
Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
microsoftCNA
5.5 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Base Score
CVSS 3.x
EPSS Score
Percentile: 13%
Affected Products (NVD)
VendorProductVersion
microsoft365_apps
-
microsoft365_apps
-
microsoftoffice_online_server
𝑥
< 16.0.10417.20097
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21258