8.3

CVE-2026-66154: sonicwall gms Improper Certificate Validation

CVSS: 8.3v3.1HighAwaiting analysis
Published 11-08-2026Last modified 12-08-2026
Open JSON

Vulnerability summary

CVE-2026-66154 is a high (CVSS 8.3) Improper Certificate Validation vulnerability in sonicwall gms. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.4% of scored vulnerabilities.

Overall risk
33/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.3/10
010
High · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · +0.07 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-08-2026
    PublishedVulnerability first disclosed.
  2. 12-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

+0.07 pp

From 0.13% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Sonicwall1 product
  • gms9.5.1 and earlier versions

1 vendor · 1 product

References

1 links