# CVE-2026-18596: Synology DiskStation Manager OTP authentication bypass

Source: https://junglewise.ai/threats/cve-2026-18596-an-authentication-bypass-using-an-alternate-path-or-channel  
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-2026-18596 · Severity: high · CVSS 8.1 · Published 2026-11-12

Synology DiskStation Manager is a network-attached storage system management platform used by organizations to manage data and backups. An authentication weakness in the one-time password (OTP) feature allows attackers with valid user credentials to bypass the OTP check, read or modify files arbitrarily, and disrupt service availability. This could lead to data theft, ransomware installation, or system outages 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-2026-18596 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18596 being exploited in the wild.

**How severe is CVE-2026-18596?** High severity, with a CVSS score of 8.1, published 12 November 2026.

**Which products and versions are affected?** Synology DiskStation Manager 7.3 before 7.3.2-86009-5, 7.4 before 7.4.1-90080-1.

**Is there a fix for CVE-2026-18596?** Yes: fixed in DiskStation Manager 7.3.2-86009-5 or above; 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-2026-18596 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-18596?** 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 DiskStation Manager 7.3.2-86009-5 or above; 7.4.1-90080-1 or above

## Technical details

An authentication bypass using an alternate path or channel (CWE-288) in the OTP component allows remote attackers holding valid user credentials to circumvent the OTP verification mechanism. The vulnerability has a CVSS 3.1 score of 8.1 with network attack vector, high complexity, and no user interaction required. Successful exploitation grants read and write access to arbitrary files on the system and enables denial-of-service attacks.

## Affected products

- Synology DiskStation Manager 7.3 before 7.3.2-86009-5, 7.4 before 7.4.1-90080-1

## Timeline

- 2026-11-12: disclosed

## 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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