Is CVE-2021-47961 in the CISA KEV catalog?

No. CVE-2021-47961 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-47961?

CVE-2021-47961 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2021-47961?

CVE-2021-47961 has an EPSS score of 0.32% (24th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-47961

HIGH

8.1

CVSS v3

NVD

Description

A plaintext storage of a password vulnerability in Synology SSL VPN Client before 1.4.5-0684 allows remote attackers to access or influence the user's PIN code due to insecure storage. This may lead to unauthorized VPN configuration and potential interception of subsequent VPN traffic when combined with user interaction.

CWE-256

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

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

Exploit Intelligence

0.32%probability of exploitation in 30 days

24thpercentile

Low risk: more likely to be exploited than 24% of all known CVEs.

References

https://www.synology.com/en-global/security/advisory/Synology_SA_26_05

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-29.