CVE-2026-21514: Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
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.
Description quoted from the CVE record (assigned by microsoft, published 2026-02-10).
Weakness: CWE-807: Reliance on Untrusted Inputs in a Security Decision
How it can be exploited
Exploitable with local access with low attack complexity needing no privileges and a user must take an action. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2026-02-10
- US federal deadline
- 2026-03-03
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Exploit Observer found 1 code repository and 1 research write-up naming this CVE.
Code repositories that name a CVE are often scanners, copies or fakes, and some are malware. Read the code before running anything.
See all 9 references on Exploit Observer
Live scores
- EPSS
- 0.016
some chance of attack soon - VEDAS
- 0.512
some exploit evidence - On CISA KEV
- Yes, since 2026-02-10
- Detection rule
- Out of scope (local)
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Microsoft Microsoft 365 Apps for Enterprise | from 16.0.1 before https://aka.ms/OfficeSecurityReleases | Not stated |
| Microsoft Microsoft Office LTSC 2021 | from 16.0.1 before https://aka.ms/OfficeSecurityReleases | Not stated |
| Microsoft Microsoft Office LTSC 2024 | from 16.0.0 before https://aka.ms/OfficeSecurityReleases | Not stated |
| Microsoft Microsoft Office LTSC for Mac 2021 | from 16.0.1 before 16.106.26020821 | Not stated |
| Microsoft Microsoft Office LTSC for Mac 2024 | from 16.0.0 before 16.106.26020821 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: https://aka.ms/OfficeSecurityReleases, 16.106.26020821.
CISA 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.
Vendor guidance:
- Microsoft Word Security Feature Bypass Vulnerability (vendor-advisory, patch)
How to detect it
This bug needs local access to exploit. VEDAS signatures cover remotely exploitable bugs for now, so there is no network rule or remote check for it. Patch it and watch your endpoint telemetry for unusual local activity.
References
Vendor advisories and patches
- Microsoft Word Security Feature Bypass Vulnerability (vendor-advisory, patch)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21514 (government-resource)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
Industry partners
