CVE-2026-66154

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Insufficient Certificate Validation in GMS Application

Publication date: 2026-08-11

Last updated on: 2026-08-28

Assigner: SonicWALL, Inc.

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 Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-11

Last Modified

2026-08-28

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-66154

EUVD

EUVD-2026-56943

Affected Vendors & Products

Vendor	Product	Version / Range
sonicwall	gms	to 9.5.1 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-295	The product does not validate, or incorrectly validates, a certificate.

Attack-Flow Graph

Executive Summary

This vulnerability involves insufficient certificate validation in a privileged communication workflow of a GMS application version 9.5.1 (Build 9510.1044) and earlier. It allows unauthorized changes under a successful man-in-the-middle (MitM) attack with controlled network conditions.

Detection Guidance

This vulnerability involves insufficient certificate validation in SonicWall GMS versions 9.5.1 (Build 9510.1044) and earlier. Detection requires checking for outdated versions and monitoring network traffic for potential MitM attacks. Use commands like 'openssl s_client -connect [target]:[port]' to inspect certificates and 'nmap -sV --script ssl-cert [target]' to verify SSL/TLS configurations.

Impact Analysis

This vulnerability could permit attackers to intercept and alter sensitive communications due to weak certificate validation. It may lead to unauthorized access, data breaches, or manipulation of system configurations, especially in privileged workflows.

Compliance Impact

This vulnerability could violate compliance requirements that mandate secure communication and data integrity, such as GDPR (data protection) and HIPAA (health information security). Insufficient validation may lead to unauthorized access or data leaks, risking regulatory penalties.

Mitigation Strategies

Update the GMS application to the latest version to address the insufficient certificate validation issue. Ensure network monitoring for unusual changes or unauthorized modifications.

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