CVE-2026-21509
published 2026-01-26CVE-2026-21509: Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
KEV
CISA Known Exploited Vulnerabilitydue 2026-02-16
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft_365_apps_for_enterprise | >= 16.0.1 < https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| microsoft | microsoft_office_2016 | >= 16.0.0 < 16.0.5539.1001 | 16.0.5539.1001 |
| microsoft | microsoft_office_2019 | >= 19.0.0 < 16.0.10417.20095 | 16.0.10417.20095 |
| microsoft | microsoft_office_ltsc_2021 | >= 16.0.1 < https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| microsoft | microsoft_office_ltsc_2024 | >= 16.0.0 < https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| microsoft | office | — | — |
| microsoft | office | — | — |
| microsoft | office_long_term_servicing_channel | — | — |
| microsoft | office_long_term_servicing_channel | — | — |
| msrc | microsoft_365_apps_for_enterprise_for_32-bit_systems | — | — |
| msrc | microsoft_365_apps_for_enterprise_for_64-bit_systems | — | — |
| msrc | microsoft_office_2016 | — | — |
| msrc | microsoft_office_2019_for_32-bit_editions | — | — |
| msrc | microsoft_office_2019_for_64-bit_editions | — | — |
| msrc | microsoft_office_ltsc_2021_for_32-bit_editions | — | — |
| msrc | microsoft_office_ltsc_2021_for_64-bit_editions | — | — |
| msrc | microsoft_office_ltsc_2024_for_32-bit_editions | — | — |
| msrc | microsoft_office_ltsc_2024_for_64-bit_editions | — | — |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vulncheck8.8HIGH
cisa7.8HIGH