CVE Tools
Track your stack

CVE-2026-21514

Microsoft Word Security Feature Bypass Vulnerability

Exploited in the wild. In CISA KEV since 2026‑02‑10. Fixed versions are out.

CVSS 3.17.8HighEPSS percentile75th1.6% chance in 30 daysCISA KEVListedsince 2026-02-10, due 2026-03-03
No public exploit knownFix4 products2 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Microsoft 365 Apps for EnterpriseAffected: ≥ 16.0.1, < https://aka.ms/OfficeSecurityReleasesUpgrade to: https://aka.ms/OfficeSecurityReleasesStated by: CVE record
  • Microsoft Office LTSC 2021Affected: ≥ 16.0.1, < https://aka.ms/OfficeSecurityReleasesUpgrade to: https://aka.ms/OfficeSecurityReleasesAffected: ≥ 16.0.0, < https://aka.ms/OfficeSecurityReleasesUpgrade to: https://aka.ms/OfficeSecurityReleasesStated by: CVE record
  • Microsoft Office LTSC for Mac 2021Affected: ≥ 16.0.1, < 16.106.26020821Upgrade to: 16.106.26020821Stated by: CVE record
  • Microsoft Office LTSC for Mac 2024Affected: ≥ 16.0.0, < 16.106.26020821Upgrade to: 16.106.26020821Stated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

Coverage timeline

0 publishers

  1. Added to CISA KEV catalog

    ·CISA KEV

Sourced from public security reporting — each date is when it was published, not when it happened. 2 further articles named this CVE in wider roundups without reporting it as a distinct event.

What it is

From the CVE record

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

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS75th
CISA KEV
CISA KEV

Listed as exploited in the wild since 2026-02-10.

US federal agencies must remediate by 2026-03-03.

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

1.6% chance of exploitation activity in the next 30 days, which ranks it in the 75th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Attention now

Rising.

Lifecycle

6 events over 135 days, from the signal feeds we watch.

  1. OpenVAS check added
  2. Patch availablerecord updated
  3. Added to CISA KEVpublished, weakness classified

Affected products

And 5 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 7.8 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

Sources

References in the record

And 2 more references. See all after sign-in

In the news

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next exploited one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Microsoft, not every advisory. This one: actively exploited.