Vulnerability in SonicWall Gms

CVE-2026-66154

An insufficient certificate validation in a privileged communication workflow, was identified in a GMS application 9.5.1 (Build 9510.1044) and earlier versions which, under a successful MitM attack and controlled network conditions, could permit unauthorized changes.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-66154: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-66154?
CVE-2026-66154 is a high-severity vulnerability in SonicWall Gms, classified under Improper Certificate Validation. CVSS score: 8.3/10. Published 2026-08-11.
How severe is CVE-2026-66154?
High severity. CVSS v3 base score is 8.3 out of 10.