CVE-2026-3091 Path traversal in Synology Presto Client
Local attackers can read or write arbitrary files and cause denial of service by placing a malicious DLL in the installer directory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-3091?
CVE-2026-3091 is a medium-severity path traversal vulnerability in Synology Presto Client, published on 24 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
An uncontrolled search path element vulnerability in Synology Presto Client before 2.1.3-0672 allows local users to read or write arbitrary files and conduct denial-of-service during installation by placing a malicious DLL in advance in the same directory as the installer.
Weakness: CWE-427
Which versions are affected by CVE-2026-3091?
It affects 1 product.
Products include Synology Presto Client.
How do I fix CVE-2026-3091?
No fix has been published for CVE-2026-3091 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-3091 being exploited?
There is no known exploitation of CVE-2026-3091 in the wild and no public exploit code.
Sources
Also known as GHSA-fj46-cfm8-7pc4.