CVE-2021-27649

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

2.00% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 80.6% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-06-23 09:50Z5 YR AGO

Last updated

2024-09-16 23:05Z2 YR AGO

Reserved

2021-02-24

Assigning CNA

synology

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

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

Weaknesses

• CWE-416Use After FreeVariant

Data version

5.1

Document digest

2a383d2d6d55b83ec0572b53cf51a35d5ae306398712203c923fdbc47eee9898

• www.synology.comhttps://www.synology.com/security/advisory/Synology_SA_20_26x_refsource_CONFIRM