Vulnerability in Synology Active Backup For Business Agent

CVE-2025-66592

An origin validation error vulnerability in Synology Active Backup for Business Agent before 3.1.0-4967 allows local users to write arbitrary files with restricted content and conduct denial-of-service during installation.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.001 (0.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 0th percentile — 0.3% 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-2025-66592: held from 0.001 to 0.001.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66592?
CVE-2025-66592 is a medium-severity vulnerability in Synology Active Backup For Business Agent, classified under Origin Validation Error. CVSS score: 6.1/10. Published 2026-05-27.
How severe is CVE-2025-66592?
Medium severity. CVSS v3 base score is 6.1 out of 10.