CVE-2026-40538 Security feature bypass in DiskStation Manager (DSM)
Attackers can bypass auto-block protections to perform brute-force attacks and read limited files on Synology DSM systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-40538?
CVE-2026-40538 is a low-severity vulnerability in Synology DiskStation Manager (DSM), published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-307
Which versions are affected by CVE-2026-40538?
How do I fix CVE-2026-40538?
No fix has been published for CVE-2026-40538 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-40538 being exploited?
There is no known exploitation of CVE-2026-40538 in the wild and no public exploit code.
Sources
Also known as GHSA-wprf-f59w-2hpp.