CVE-2026-4793 is a high severity (CVSS 7.3) incorrect default permissions flaw in Synology Assistant on Windows. Local users can read or write arbitrary files and cause denial of service during installation. Update to Synology Assistant 7.0.7-50095 or later. The steps below show how to check your version and what to change.
What's affected
- Synology Assistant: versions before 7.0.7-50095. Fixed in 7.0.7-50095.
The record lists Microsoft Windows as the platform. Synology's advisory SA_26_12 rates the issue Important with a CVSS 3.1 base score of 7.3, matching the record's High. It lists no workaround.
The attacker must be a local user, and the exposure is tied to the installation of the program.
How to check if you're exposed
Open Settings, then Apps, then Installed apps on Windows and look for Synology Assistant, or open the program and read its About screen. A version before 7.0.7-50095 is affected.
To find installs across many machines, query your endpoint management tool for the Synology Assistant display name and version.
What to do now
- Update Synology Assistant to 7.0.7-50095 or later on every Windows host that has it.
- Remove the tool from machines that do not need it. It is a discovery utility and many hosts will not use it.
- Install and update from a clean, administrator-controlled path, since the flaw is tied to installation.
- Check Synology's advisory SA_26_12 for any other affected products you run.
Why it matters
The record lists CWE-276, incorrect default permissions. During installation, files or folders are created with permissions that let ordinary local users read or change them. If an installer or program later loads or runs those files, the permissions can become a route to elevated access or to disrupting the system.
Local flaws like this matter on shared machines, jump hosts and terminal servers more than on a single-user laptop. The record does not mark this CVE as known exploited.
For most organizations the first problem is knowing where the tool is installed. Synology Assistant is a small utility that administrators tend to install once and forget, often on laptops and jump hosts. Use your endpoint management or software inventory to list every machine that has it, record the version, and update or remove each one. After the update, confirm that the install folder permissions are what you expect for a program under Program Files, so ordinary users cannot write to it.
Quick check
Does this affect my NAS?
The advisory concerns the Synology Assistant desktop utility for Windows, not NAS firmware. Check the advisory for other affected products.
Can an outside attacker use this?
The record describes a local user, so an attacker needs access to the machine first.
Sources
Last reviewed: 18 October 2026.
