CVE-2026-32661: Stack-based buffer overflow vulnerability exists in GUARDIANWALL MailSuite and GUARDIANWALL Mail Security Cloud (SaaS…

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 13 May 2026. It cites 1 public report, the first from 13 May 2026.

• jvn.jp

How likely is exploitation in the next 30 days?

0.5%

Down from 0.7% on 22 Oct 2026.

EPSS score, percentile 40.8 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

9.3 Critical

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• Ver 1.4.00 to Ver 2.4.26
• versions before the maintenance on April 30
• 2026

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

Stack-based buffer overflow vulnerability exists in GUARDIANWALL MailSuite and GUARDIANWALL Mail Security Cloud (SaaS version). If a remote attacker sends a specially crafted request to the product's web service, arbitrary code may be executed when the product is configured to run pop3wallpasswd with grdnwww user privilege.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline