CVE-2026-21514 Microsoft Office: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Mar 3, 2026
What to do
- Install Microsoft's security update for Office. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Turn on automatic updates for the operating system and for Office, PDF and archive apps.
- Be careful with unexpected attachments — documents, .zip/.rar files and shortcuts are common bait.
- Use a normal (non-admin) account day to day and keep built-in protection like Microsoft Defender on.
Who is affected
Could reach you. This one is aimed at devices or apps of the kind people own.
What's at risk: Your files, saved passwords and accounts. Many of these let a program that is already running gain full administrator control.
The details
- Official name
- Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Vulnerability
- Product
- Microsoft Office
- CISA description
- Microsoft Office Word contains a reliance on untrusted inputs in a security decision vulnerability that could allow an authorized attacker to elevate privileges locally.
- Type of flaw
- Software flaw (CWE-807)
- Confirmed exploited
- Feb 10, 2026
- US federal patch deadline
- Mar 3, 2026
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Answering about CVE-2026-21514 ·
Questions about CVE-2026-21514
Is CVE-2026-21514 being exploited?
Yes. CISA added CVE-2026-21514 to its Known Exploited Vulnerabilities catalog on Feb 10, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-21514?
Install Microsoft's security update for Office. If no update exists, follow the vendor's workaround or stop using the product until one ships. Turn on automatic updates for the operating system and for Office, PDF and archive apps.
Am I affected by CVE-2026-21514?
Only if you use Microsoft Office. This one is aimed at devices or apps of the kind people own.