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CVE-2021-26565Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3…
- 8.3HighCVSS base score
- 0.74%Exploitation in 30 daysEPSS · top 45% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows man-in-the-middle attackers to obtain sensitive information via an HTTP session.
Timeline
ID reserved
By synology
- 24 days later
· 24 days later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| synologyCNA (assigner) | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.74% · top 45% of all CVEs (14 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Affected products
Synology · Synology DiskStation Manager (DSM)
- affected unspecified – < 6.2.3-25426-3
References
References2
- https://www.synology.com/security/advisory/Synology_SA_20_26 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1160 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-13363 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-26565)Record last updated .