EXECUTIVE SUMMARY:
CVE-2026-32661 with a CVSS score of 9.8 is a critical stack-based buffer overflow vulnerability in GUARDIANWALL MailSuite, a mail security solution provided by Canon Marketing Japan Inc., specifically affecting GUARDIANWALL MailSuite (On-premises version) with all versions from Ver 1.4.00 to Ver 2.4.26, and GUARDIANWALL Mail Security Cloud (SaaS version) with versions deployed before the April 30, 2026 maintenance cycle. This flaw is rooted in the pop3wallpasswd command (CWE-121) and allows a remote, unauthenticated attacker to send a specially crafted request to the product's web service, subject to specific technical requirements for exploitation including configuration to run pop3wallpasswd with grdnwww user privilege. If exploited, the impact is severe, potentially allowing for arbitrary code execution on the target system, giving the attacker full control over the compromised system. The business impact and consequences of exploitation are severe, with potentially significant disruptions to operations, as noted by the vendor, and a significant security risk to sensitive information processed by the affected systems.[/subscribe_to_unlock_form]
EXECUTIVE SUMMARY:
CVE-2026-32661 with a CVSS score of 9.8 is a critical stack-based buffer overflow vulnerability in GUARDIANWALL MailSuite, a mail security solution provided by Canon Marketing Japan Inc., specifically affecting GUARDIANWALL MailSuite (On-premises version) with all versions from Ver 1.4.00 to Ver 2.4.26, and GUARDIANWALL Mail Security Cloud (SaaS version) with versions deployed before the April 30, 2026 maintenance cycle. This flaw is rooted in the pop3wallpasswd command (CWE-121) and allows a remote, unauthenticated attacker to send a specially crafted request to the product's web service, subject to specific technical requirements for exploitation including configuration to run pop3wallpasswd with grdnwww user privilege. If exploited, the impact is severe, potentially allowing for arbitrary code execution on the target system, giving the attacker full control over the compromised system. The business impact and consequences of exploitation are severe, with potentially significant disruptions to operations, as noted by the vendor, and a significant security risk to sensitive information processed by the affected systems.[emaillocker id="1283"]
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The following reports contain further technical details:
https://securityonline.info/guardianwall-mailsuite-vulnerability-cve-2026-32661-exploited/