CVE-2021-26563

Name: CVE-2021-26563
Creator: NVD / NIST
Published: 2021-02-26T22:15:20.143+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.7/10EPSS 0.51%

Last modified Jun 17, 2026

CVE-2021-26563 is a medium-severity vulnerability rated 6.7/10 on the CVSS scale. 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.. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.7/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.51%

39.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Synology	Diskstation Manager	< 6.2.4-25553
Synology	Vs960hd Firmware	All versions
Synology	Skynas Firmware	All versions
Synology	Diskstation Manager Unified Controller	3.0

References

https://www.synology.com/security/advisory/Synology_SA_21_03Vendor Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1158Exploit, Third Party Advisory
https://www.synology.com/security/advisory/Synology_SA_21_03Vendor Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1158Exploit, Third Party Advisory

Timeline

Published: Feb 26, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26563?

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.

How severe is CVE-2021-26563?

CVE-2021-26563 has a CVSS score of 6.7/10 (MEDIUM severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26563?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26563?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST