Windows 10 Version 1607: Use After Free
CVE-2026-105504 is a high-severity use after free vulnerability in Windows 10 Version 1607 from Microsoft, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 10.0.14393.9688 as the first without the flaw, so updating Windows 10 Version 1607 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Windows 10 Version 1607 to 10.0.14393.9688 or a later version.
- Update Windows 10 Version 1809 to 10.0.17763.9487 or a later version.
- Update Windows 10 Version 21H2 to 10.0.19044.7846 or a later version.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 10 Version 1607 | 10.0.14393.0 up to, but not including, 10.0.14393.9688 | 10.0.14393.9688 |
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 up to, but not including, 10.0.17763.9487 | 10.0.17763.9487 |
| Microsoft | Windows 10 Version 21H2 | 10.0.19044.0 up to, but not including, 10.0.19044.7846 | 10.0.19044.7846 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 up to, but not including, 10.0.19045.7846 | 10.0.19045.7846 |
| Microsoft | Windows 11 version 23H2 | 10.0.22631.0 up to, but not including, 10.0.22631.7711 | 10.0.22631.7711 |
| Microsoft | Windows 11 Version 24H2 | 10.0.26100.0 up to, but not including, 10.0.26100.9974 | 10.0.26100.9974 |
| Microsoft | Windows 11 Version 25H2 | 10.0.26200.0 up to, but not including, 10.0.26200.9974 | 10.0.26200.9974 |
| Microsoft | Windows 11 version 26H1 | 10.0.28000.0 up to, but not including, 10.0.28000.3501 | 10.0.28000.3501 |
| Microsoft | Windows 11 Version 26H2 | 10.0.26300.0 up to, but not including, 10.0.26300.9974 | 10.0.26300.9974 |
| Microsoft | Windows Server 2016 | 10.0.14393.0 up to, but not including, 10.0.14393.9688 | 10.0.14393.9688 |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 up to, but not including, 10.0.14393.9688 | 10.0.14393.9688 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 up to, but not including, 10.0.17763.9487 | 10.0.17763.9487 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 up to, but not including, 10.0.17763.9487 | 10.0.17763.9487 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 up to, but not including, 10.0.20348.5870 | 10.0.20348.5870 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 up to, but not including, 10.0.26100.33822 | 10.0.26100.33822 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 up to, but not including, 10.0.26100.33822 | 10.0.26100.33822 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (microsoft.com).
Official description
An elevation of privilege vulnerability exists in the way that the Windows Kernel handles objects in memory. An attacker who successfully exploited the vulnerability could execute code with elevated permissions. To exploit the vulnerability, a locally authenticated attacker could run a specially crafted application. The security update addresses the vulnerability by ensuring the Windows Kernel properly handles objects in memory.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Recent Use After Free vulnerabilities
- 8.8 High severity
- 7.1 High severity
- 10.0 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 8.4 High severity
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