CVE-2026-19820: Backblaze Client for Windows Improper Link Resolution Vulnerability
A vulnerability in the Backblaze Client allows a local user to make the system not bootable by creating a link from Backblaze's folder to Windows OS system files during a backup. Successful exploitation requires an administrator-level system change that results in the absence of specific Windows OS security controls. This vulnerability is due to improper link resolution.
Affected Software
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Systems running the Backblaze Client for Windows are exposed if a local user can create a link from Backblaze's folder to Windows operating system files during a backup. Exploitation also requires an administrator-level system change that removes specific Windows OS security controls.
What is the likely impact of successful exploitation?
A successful attack can make the affected Windows system unbootable.
Does exploitation require remote access or elevated privileges?
The described attack requires a local user and an administrator-level system change. The provided information does not describe a remote exploitation path.