CVE-2021-26563
Synology
- Published
- 26 February 2021
- Last modified
- 17 June 2026
- CVSS
- 6.7 v3.1
- Severity
- medium
- EPSS
- 0.5% (42th pct)
- CISA KEV
- Not listed
- NVD status
- Modified
- Weaknesses
- CWE-863
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Description
Incorrect authorization vulnerability in synoagentregisterd in Synology DiskStation Manager (DSM) before 6.2.4-25553 allows local users to execute arbitrary code via unspecified vectors.
Exploitation
Not listed in the CISA Known Exploited Vulnerabilities catalogue as of 2026.09.04. That is an absence of confirmed public exploitation, not evidence that exploitation has not occurred. EPSS models a 0.5% probability of exploitation activity in the next 30 days.
Affected products
| Product | Vendor | Type | Versions named |
|---|---|---|---|
| VS960HD | Synology | unknown | < 2.2.3-1505, < 2.3.6-1720 |
References
Vendor advisory and patch
- https://www.synology.com/security/advisory/Synology_SA_21_03
- https://www.synology.com/security/advisory/Synology_SA_21_03
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1158 exploit
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1158 exploit
Record assembled from NVD, CISA KEV 2026.09.04 and FIRST EPSS 2026-09-04. Affected products are those NVD's CPE configuration names that fall inside this site's scope; a CVE may affect products outside it.