Medium severity · published May 27, 2026
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…
5.6
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 0% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SA
Synology Active Backup for Business Agent · Synology
before 3.1.0-4967 · source: vendor
AB
Active Backup For Business Agent · Synology
before 3.1.0-4967 · source: NVD
Affected product
SA
Synology Active Backup for Business Agent
Synology
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66592
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-66592
Vendor Advisory
https://www.synology.com/en-global/security/advisory/Synology_SA_25_16
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