Executive brief
A vulnerability exists in the Windows Server Message Block (SMB) protocol, which is used for sharing files and printers across a network. An attacker who already has basic access to a computer could exploit this flaw to view sensitive information that they should not be able to see. This could lead to the exposure of confidential system data or user information, though it does not allow the attacker to modify files or crash the system.
Technical details
A vulnerability classified as 'Use of Uninitialized Resource' (CWE-908) exists within the Microsoft Windows SMB implementation. The flaw allows a local, authenticated attacker to gain access to sensitive information by interacting with the SMB service. Because the system fails to properly initialize a resource before it is used or returned, memory contents may be leaked to the attacker. The attack requires local access and low privileges, but no user interaction is necessary. Microsoft has released security updates to address this issue across various versions of Windows 10, Windows 11, and Windows Server 2012.
Affected products
- Microsoft Windows 10 1607, 1809, 21H2, 22H2
- Microsoft Windows 11 24H2, 25H2, 26H1
- Microsoft Windows Server 2012 All editions including Server Core
Timeline
- 2026-07-14: disclosed: Initial publication by Microsoft and NVD
- 2026-07-14: advisory: Microsoft Security Update Guide published