# CVE-2026-81557: Synology DiskStation Manager improper input neutralization in DSMNotify

Source: https://junglewise.ai/threats/cve-2026-81557-an-improper-neutralization-of-input-during-web-page-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-81557 · Severity: medium · CVSS 5.4 · Published 2026-11-12

Synology DiskStation Manager is a software suite that manages network-attached storage devices for businesses and enterprises. An improper input handling vulnerability in the DSMNotify component allows authenticated users to read or write files on the system, potentially exposing sensitive data or enabling unauthorized modifications. This could compromise data confidentiality and integrity on affected storage systems.

Technologies: [Synology DiskStation Manager](https://junglewise.ai/threats/technologies/diskstation-manager). Vendors: [Synology](https://junglewise.ai/threats/vendors/synology).

## 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

## References

- [https://www.synology.com/en-global/security/advisory/Synology_SA_26_18](https://www.synology.com/en-global/security/advisory/Synology_SA_26_18)

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