CVE-2026-83789

Heap-based buffer overflow in Windows SMB Client allows an unauthorized attacker to elevate privileges over a network.

Base score8.8/ 10

SeverityHighCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityHigh

Attack vectorNetworkAV

Attack complexityLowAC

Privileges requiredNonePR

User interactionRequiredUI

ScopeUnchangedS

Confidentiality impactHighC

Integrity impactHighI

Availability impactHighA

Exploit maturityUnprovenE

CVSS vector stringCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering Authoritymicrosoft

Last updatedOct 30, 2026 19:10:35 UTC

PublishedOct 13, 2026 19:00:55 UTC

ReservedAug 31, 2026 23:02:37 UTC