CVE-2025-62221 Microsoft Windows: memory-safety flaw
In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.
Confirmed exploited by CISA on · US federal patch deadline Dec 30, 2025
What to do
- Install Microsoft's security update for Windows. 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 Windows Use After Free Vulnerability
- Product
- Microsoft Windows
- CISA description
- Microsoft Windows Cloud Files Mini Filter Driver contains a use after free vulnerability that can allow an authorized attacker to elevate privileges locally.
- Type of flaw
- Memory-safety flaw (CWE-416)
- Confirmed exploited
- Dec 9, 2025
- US federal patch deadline
- Dec 30, 2025
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Answering about CVE-2025-62221 ·
Questions about CVE-2025-62221
Is CVE-2025-62221 being exploited?
Yes. CISA added CVE-2025-62221 to its Known Exploited Vulnerabilities catalog on Dec 9, 2025, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2025-62221?
Install Microsoft's security update for Windows. 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-2025-62221?
Only if you use Microsoft Windows. This one is aimed at devices or apps of the kind people own.