CVE & CISA-KEV CatalogNVD
CVE-2026-20957
CRITICAL7.8
CVSS v3
Description
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
CVSS v3 Vector
Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Exploit Intelligence
0.45%probability of exploitation in 30 days
36thpercentile
Low risk: more likely to be exploited than 36% of all known CVEs.
References
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Start freeThis 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 2026-01-14.