Synology Presto Client <2.1.3-0672 UNC Search Path Vulnerability
CVE-2026-3091 Published on February 24, 2026

An uncontrolled search path element vulnerability in Synology Presto Client before 2.1.3-0672 allows local users to read or write arbitrary files during installation by placing a malicious DLL in advance in the same directory as the installer.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-3091 can be exploited with local system access, requires user interaction and a small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
LOCAL
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a DLL preloading Vulnerability?

The product uses a fixed or controlled search path to find resources, but one or more locations in that path can be under the control of unintended actors.

CVE-2026-3091 has been classified to as a DLL preloading vulnerability or weakness.


Affected Versions

Synology Presto Client:

Exploit Probability

EPSS
0.01%
Percentile
1.79%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.