Information disclosure in Synology DiskStation Manager
Priority MEDIUM 42CWE-201Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-201.
Summary
Insertion of sensitive information into sent data vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to execute arbitrary commands via inbound QuickConnect traffic.
Why it matters now
EPSS 0.01508 74th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Synology DiskStation Manager (DSM) (Synology): 6.2.3-25426-3
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Synology | Synology DiskStation Manager (DSM) | before 6.2.3-25426-3 | 6.2.3-25426-3 | Patch available | CNA |
- Synology DiskStation Manager (DSM) VendorSynology Affected before 6.2.3-25426-3 Fixed in 6.2.3-25426-3 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:synology:diskstation_manager:*:*:*:*:*:*:*:* | before 6.2.3-25426-3 | Vulnerable | Synology |
| cpe:2.3:o:synology:vs960hd_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Synology |
| cpe:2.3:h:synology:vs960hd:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Synology |
| cpe:2.3:o:synology:skynas_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Synology |
| cpe:2.3:h:synology:skynas:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Synology |
| cpe:2.3:o:synology:diskstation_manager_unified_controller:3.0:*:*:*:*:*:*:* | 3.0 | Vulnerable | Synology |
| cpe:2.3:h:synology:uc3200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Synology |
- cpe:2.3:o:synology:diskstation_manager:*:*:*:*:*:*:*:* Versions before 6.2.3-25426-3 Vulnerable ·Synology
- cpe:2.3:o:synology:vs960hd_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Synology
- cpe:2.3:h:synology:vs960hd:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Synology
- cpe:2.3:o:synology:skynas_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Synology
- cpe:2.3:h:synology:skynas:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Synology
- cpe:2.3:o:synology:diskstation_manager_unified_controller:3.0:*:*:*:*:*:*:* Versions 3.0 Vulnerable ·Synology
- cpe:2.3:h:synology:uc3200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Synology
Remediation
- Fix · CNA Synology DiskStation Manager (DSM) (Synology) Fixed in 6.2.3-25426-3
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Synology DiskStation Manager (DSM) 6.2.3-25426-3
6 records Highest priority Priority MEDIUM 4 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2021-08286 Out-of-bounds write in Synology DiskStation ManagerPriority MEDIUM 43
- TI-2021-08285 Stack-based buffer overflow in Synology DiskStation ManagerPriority MEDIUM 43
- TI-2021-08284 Cleartext transmission of sensitive information in Synology DiskStation ManagerPriority MEDIUM 40
Timeline
- 2026-10-02 Threatist record created from CVE-2021-26566
- 2026-10-03 Alias added: GHSA-x5fh-xfvr-gg7m
References
More Synology Diskstation Manager vulnerabilities
- TI-2021-02242 Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer… KEVCVSS 3.1HIGH 7.8
- TI-2018-01076 Out-of-bounds write in Netatalk CVSS 3.1CRITICAL 9.8
- TI-2017-10594 Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a… CVSS 3.1CRITICAL 9.8
- TI-2013-05716 webman/imageSelector.cgi in Synology DiskStation Manager (DSM) 4.0 before 4.0-2259, 4.2… CVSS 2.0HIGH 10.0
- TI-2021-19843 Out-of-bounds read in Samba CVSS 3.1HIGH 8.8
- TI-2017-11636 Command injection in Synology DiskStation Manager CVSS 3.0HIGH 8.8
Sources
- CVE-2021-26566 · CVE Program
- CVE-2021-26566 · NVD
- FIRST EPSS
- GHSA-x5fh-xfvr-gg7m · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences