Quick answers
- Is CVE-2026-81557 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-81557 being exploited in the wild.
- How severe is CVE-2026-81557?
- Medium severity, with a CVSS score of 5.4, published 12 November 2026.
- Which products and versions are affected?
- Synology DiskStation Manager before 7.3.2-86009-5 and 7.4.1-90080-1.
- Is there a fix for CVE-2026-81557?
- Yes: fixed in DSM 7.3.2-86009-5, DSM 7.4.1-90080-1 or above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-81557 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-81557?
- Check whether you run Synology DiskStation Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: DSM 7.3.2-86009-5, DSM 7.4.1-90080-1 or above
Technical details
An improper neutralization of input during web page generation (CWE-79 or similar) in DSMNotify allows remote authenticated users to read or write arbitrary files. The vulnerability requires prior authentication but presents no additional user interaction barrier. A successful exploit grants file read/write access, enabling data exfiltration or system manipulation.
Affected products
- Synology DiskStation Manager before 7.3.2-86009-5 and 7.4.1-90080-1
Timeline
- 2026-11-10: disclosed
- 2026-11-12: advisory