CVE & CISA-KEV Catalog

CVE-2026-21258

HIGH
5.5
CVSS v3
NVD

Description

Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

CWE-20Improper Input ValidationCWE-125Out-of-bounds Read

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityNone
AvailabilityNone

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

Exploit Intelligence

0.60%probability of exploitation in 30 days
44thpercentile

Moderate risk: more likely to be exploited than 44% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-11.