CVE-2026-21514

high

Description

Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized attacker to bypass a security feature locally.

From the Tenable Blog

CVE-2026-21514 FAQ: OLE bypass N-Day in Microsoft Word | Tenable®

Published: 2026-03-17

The OLE bypass N-day vulnerability (CVE-2026-21514) in Microsoft Word exposes nearly 14 million assets. Attackers can exploit this flaw to bypass security prompts, enabling deployment of malware and establishing persistent access without triggering user warnings.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21514

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-21514

https://www.malwarebytes.com/blog/news/2026/02/february-2026-patch-tuesday-includes-six-actively-exploited-zero-days

https://www.infosecurity-magazine.com/news/microsoft-six-zero-day-feb-2026/

https://www.helpnetsecurity.com/2026/02/11/february-2026-patch-tuesday/

https://thehackernews.com/2026/02/microsoft-patches-59-vulnerabilities.html

https://securityaffairs.com/187855/security/u-s-cisa-adds-microsoft-office-and-microsoft-windows-flaws-to-its-known-exploited-vulnerabilities-catalog.html

https://www.theregister.com/2026/02/10/microsofts_valentines_gift_to_admins/

https://www.securityweek.com/6-actively-exploited-zero-days-patched-by-microsoft-with-february-2026-updates/

https://www.cisa.gov/news-events/alerts/2026/02/10/cisa-adds-six-known-exploited-vulnerabilities-catalog

https://securityaffairs.com/187848/uncategorized/microsoft-patch-tuesday-security-updates-for-february-2026-fix-six-actively-exploited-zero-days.html

https://cyberscoop.com/microsoft-patch-tuesday-february-2026/

https://krebsonsecurity.com/2026/02/patch-tuesday-february-2026-edition/

https://www.tenable.com/blog/operation-epic-fury-why-exposure-data-changes-everything-about-irans-cyber-kinetic-campaign

https://www.tenable.com/blog/faq-on-cve-2026-21514-ole-bypass-n-day-in-microsoft-word

https://www.tenable.com/blog/microsofts-february-2026-patch-tuesday-addresses-54-cves-cve-2026-21510-cve-2026-21513

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21514

Details

Source: Mitre, NVD

Published: 2026-02-10

Updated: 2026-02-11

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.06655

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest

Detections

Analytics