Synology DSM <7.2.2: Brute-Force Auth Allows Limited File Read
CVE-2026-40538 Published on September 18, 2026
An improper restriction of excessive authentication attempts vulnerability in Auto block in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote attackers to read limited files via brute-force attacks.
Vulnerability Analysis
CVE-2026-40538 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
Improper Restriction of Excessive Authentication Attempts
The software does not implement sufficient measures to prevent multiple failed authentication attempts within in a short time frame, making it more susceptible to brute force attacks.
Products Associated with CVE-2026-40538
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Affected Versions
Synology DiskStation Manager (DSM):- Version 7.3.2 and below 7.3.2-86009-2 is affected.
- Version 7.2.2 and below 7.2.2-72806-7 is affected.
- Version 7.2.1 and below 7.2.1-69057-10 is affected.
- Before 7.2.1 is unknown.