High severity7.8NVD Advisory· Published Jan 13, 2026· Updated Jun 17, 2026

CVE-2026-20957

Description

Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Microsoft/Office Online Servercpe-rescue2 versions
16.0.0.0+ 1 more
- (no CPE)range: 16.0.0.0
- cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*range: <16.0.10417.20083
Microsoft/Excel 2007 SP3cpe-rescue
Range: 16.0.0.0
Microsoft/Officecpe-rescue3 versions
16.0.1+ 2 more
- (no CPE)range: 16.0.1
- (no CPE)range: 16.0.0
- cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:*:*
Microsoft/Office For Maccpe-rescue2 versions
16.0.1+ 1 more
- (no CPE)range: 16.0.1
- (no CPE)range: 16.0.0
Microsoft/365 Apps2 versions
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*+ 1 more
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*
Microsoft/Excel
cpe:2.3:a:microsoft:excel:2016:*:*:*:*:*:*:*
Microsoft/Office Long Term Servicing Channel6 versions
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*+ 5 more
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:*
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:macos:*:*
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:*
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:*
- cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:macos:*:*
Microsoft/Microsoft 365 Apps for Enterprisev5
Range: 16.0.1
Microsoft/Office Excelllm-fuzzy
Microsoft/Office Visiocpe-rescue
Range: 19.0.0