Vulnerability in Synology Presto Client

CVE-2026-3091

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (3.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3091: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3091?
CVE-2026-3091 is a medium-severity vulnerability in Synology Presto Client, classified under Uncontrolled Search Path Element. CVSS score: 6.7/10. Published 2026-02-24.
How severe is CVE-2026-3091?
Medium severity. CVSS v3 base score is 6.7 out of 10.