CVEs / CVE-2026-21514
CVE-2026-21514: Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Vulnerability
- Known exploited in the CISA KEV catalog since 10 Feb 2026
- high 7.8 CVSS 3.1 (from the CNA)
- EPSS 1.58% chance of exploitation in the next 30 days, higher than 75% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Microsoft Office Word contains a reliance on untrusted inputs in a security decision vulnerability that could allow an authorized attacker to elevate privileges locally.
Description
Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized attacker to bypass a security feature locally.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Microsoft 365 Apps for Enterprise | from 16.0.1, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Office LTSC 2021 | from 16.0.1, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Office LTSC 2024 | from 16.0.0, before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft Microsoft Office LTSC for Mac 2021 | from 16.0.1, before 16.106.26020821 | 16.106.26020821 |
| Microsoft Microsoft Office LTSC for Mac 2024 | from 16.0.0, before 16.106.26020821 | 16.106.26020821 |
Exploitation
| In CISA KEV since | 10 Feb 2026 |
|---|---|
| Due date for US federal agencies | 3 Mar 2026 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
Severity
| CVSS 3.1 | 7.8 highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-807 |
References
- CVE-2026-21514 on NVD
- CVE-2026-21514 in the CISA KEV catalog
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21514 (cited by CISA)
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21514 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21514 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.