CVE-2026-85821 Windows Universal Disk Format File System Driver (UDFS) Information Disclosure Vulnerability
An out-of-bounds read in the Windows UDFS driver allows local attackers to disclose sensitive information.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85821?
CVE-2026-85821 is a medium-severity vulnerability in Microsoft Windows 10 1607, published on 13 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Out-of-bounds read in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to disclose information locally.
Weakness: CWE-125
Which versions are affected by CVE-2026-85821?
It affects 14 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 8 more.
How do I fix CVE-2026-85821?
No fix has been published for CVE-2026-85821 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-85821 being exploited?
There is no known exploitation of CVE-2026-85821 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-xr6q-jcq9-rp24.