High severity · published Aug 11, 2026
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…
8.3
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Adjacent
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GM
GMS · SonicWall
9.5.1 and earlier versions · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66154
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66154
psirt.global.sonicwall.com
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0011
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