CVE-2021-26564 json
Cleartext transmission of sensitive information vulnerability in synorelayd in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allo…
published 2021-02-26 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-13362
- cvss
- 8.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 52%
- public exploits
- 0
- none known
Summary
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 spoof servers via an HTTP session.
Patch / fix
- Synology Synology DiskStation Manager (DSM) 6.2.3-25426-3
Exploit prediction
0.67% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- talosintelligence.com https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1160 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVD | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N |
| NVD | 2.0 | 5.8 | AV:N/AC:M/Au:N/C:P/I:P/A:N |
Affected products
- Synology Synology DiskStation Manager (DSM)
Classification
- Weakness
-
- CWE-319 Cleartext Transmission of Sensitive Information
References
-
talosintelligence.com
/vulnerability_reports/TALOS-2020-1160
exploit, third-party-advisory
-
synology.com
/security/advisory/Synology_SA_20_26
vendor-advisory
Sources
- CVE List CVE-2021-26564
- NVD CVE-2021-26564
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