What is CVE-2020-27650?

CVE-2020-27650 is a medium-severity vulnerability in Synology Diskstation Manager, classified under Sensitive Cookie in HTTPS Session Without 'Secure' Attribute. CVSS score: 5.8/10. Published 2020-10-29.

How severe is CVE-2020-27650?

Medium severity. CVSS v3 base score is 5.8 out of 10.

Vulnerability in Synology Diskstation Manager

CVE-2020-27650

Synology DiskStation Manager (DSM) before 6.2.3-25426-2 does not set the Secure flag for the session cookie in an HTTPS session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an HTTP session.

Published 2020-10-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.006 (46.6th percentile), scored 2026-11-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Synology Diskstation Manager
Synology Diskstation Manager (Dsm) — versions unspecified
Synology Skynas
Synology Skynas Firmware

Weakness classification (CWE)

References

www.synology.com/security/advisory/Synology_SA_20_18 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-27650?: CVE-2020-27650 is a medium-severity vulnerability in Synology Diskstation Manager, classified under Sensitive Cookie in HTTPS Session Without 'Secure' Attribute. CVSS score: 5.8/10. Published 2020-10-29.
How severe is CVE-2020-27650?: Medium severity. CVSS v3 base score is 5.8 out of 10.