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Vulnerability record · CVE-2021-26562 · published 26 February 2021

CVE-2021-26562: Synology diskstation manager out-of-bounds write vulnerability

Synology · Diskstation Manager

Out-of-bounds write vulnerability in synoagentregisterd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to execute arbitrary code via syno_finder_site HTTP header.

8.1 CVSS 3.1 High EPSS 1.9% · top 21.1% CWE-787 · Out-of-bounds write
8.1CVSS 3.1 base score, v2 6.8
1.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
4Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

Out-of-bounds write vulnerability in synoagentregisterd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to execute arbitrary code via syno_finder_site HTTP header.

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

Affected products

4 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.synology.com/security/advisory/Synology_SA_20_26 Vendor Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1159 ExploitThird Party Advisory
https://www.synology.com/security/advisory/Synology_SA_20_26 Vendor Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1159 ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-26562), CISA KEV, FIRST EPSS (scores of 2026-10-02). This page is refreshed as NVD updates the record.