Known exploited vulnerability
CVE-2026-21514
The short answer
CVE-2026-21514 affects Microsoft Microsoft 365 Apps for Enterprise and is rated high (CVSS 7.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-02-10: attackers are using it, so patch it first.
What it is
Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized attacker to bypass a security feature locally.
Weakness: CWE-807.
Severity
7.8 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Feb 10, 2026
Federal due date Mar 3, 2026
EPSS, next 30 days
1.6%
Higher than 76% of scored CVEs
How it can be exploited
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected products
Microsoft 365 Apps for Enterprise, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, Microsoft Office LTSC for Mac 2024. NVD's record lists the exact affected versions.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21514 Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21514 US Government Resource
Questions
Is CVE-2026-21514 being exploited?
Yes. CISA added CVE-2026-21514 to its Known Exploited Vulnerabilities catalog on 2026-02-10, with a federal remediation due date of 2026-03-03.
How do I fix CVE-2026-21514?
CISA's 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
Related
Latest CVEs this week
Critical and High CVEs from the last 7 days, with KEV and EPSS.
Exploited vulnerabilities by vendor
Every vendor in CISA's KEV catalog, with its count.
Microsoft exploited vulnerabilities
Everything CISA lists as exploited for Microsoft.
Vulnerability watch
A briefing and a fix pull request when an advisory hits your dependencies.
Know the day a CVE lands in your code
Connect a GitHub repository and ZeusQA checks its dependencies daily, briefs each advisory and opens the fix. Three test runs free, no card.