CVE-2026-40539

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.11% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 1.4% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-09-18.

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

2026-09-18 08:29Z1 MO AGO

Last updated

2026-09-18 10:40Z1 MO AGO

Reserved

2026-04-14

Assigning CNA

synology

Record state

PUBLISHED

Severity

High (CVSS 7.1)

CNA CVSS vector

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

Weaknesses

• CWE-295Improper Certificate ValidationBase

Data version

5.2

Document digest

d725542e86043300b8130792df269d16e3080ca32e81f1225d5f8af7d2c37547

• www.synology.comSynology-SA-26:06 DSMhttps://www.synology.com/en-global/security/advisory/Synology_SA_26_06vendor-advisory