Stack-based Buffer Overflow in GUARDIANWALL MailSuite and Mail Security Cloud by GUARDIANWALL
CVE-2026-32661

9.3CRITICAL

Key Information:

Vendor

Canon Marketing Japan Inc.

Status
Guardianwall Mailsuite (on-premises Version)
Guardianwall Mail Security Cloud (saas Version)
Vendor
CVE Published:
13 May 2026

What is CVE-2026-32661?

A stack-based buffer overflow vulnerability exists in GUARDIANWALL MailSuite and GUARDIANWALL Mail Security Cloud. An attacker can exploit this vulnerability by sending a specially crafted request to the web service of the affected product. If the application is configured to run pop3wallpasswd with grdnwww user privileges, it may lead to the execution of arbitrary code, posing a significant risk to the integrity and security of the system.

Affected Version(s)

GUARDIANWALL Mail Security Cloud (SaaS version) versions before the maintenance on April 30

GUARDIANWALL Mail Security Cloud (SaaS version) 2026

GUARDIANWALL MailSuite (On-premises version) Ver 1.4.00 to Ver 2.4.26

References

https://jvn.jp/en/jp/JVN35567473/

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

CVSS V3.0

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.