Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-13672 Overview
An authorization bypass through user-controlled key vulnerability in the SSOAuth in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to read or write arbitrary files and conduct denial-of-service attacks.
Critical Impact
Affected Products
- Synology SSOAuth in Synology DiskStation Manager (DSM): see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-12: CVE-2026-13672 published to the National Vulnerability Database by security@synology.com
- 2026-11-12: last updated in the NVD database
Technical Details for CVE-2026-13672
Vulnerability Analysis
CVE-2026-13672 is a Insecure Direct Object Reference weakness (CWE-639: Insecure Direct Object Reference) in Synology SSOAuth in Synology DiskStation Manager (DSM). Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Changing an ID in a request exposes another user's data.
With a CVSS base score of 8.8, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The weakness is classified as CWE-639: Insecure Direct Object Reference. Changing an ID in a request exposes another user's data.
Attack Vector
Based on the CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Detection Methods for CVE-2026-13672
Detection Strategies
- Inventory every instance of Synology SSOAuth in Synology DiskStation Manager (DSM) and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Synology SSOAuth in Synology DiskStation Manager (DSM) application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-13672
Immediate Actions Required
- Apply the fixed version of Synology SSOAuth in Synology DiskStation Manager (DSM) named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Synology SSOAuth in Synology DiskStation Manager (DSM).
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
- CWE-639: Insecure Direct Object Reference More CVEs with this weakness
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
Related CVEs
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A missing critical step in authentication vulnerability in the Auth API in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to read or write arbitrary files and conduct denial-of-service attacks.
An improper link resolution before file access vulnerability in the thumb in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to write arbitrary files and conduct denial-of-service attacks.
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