CVE-2025-42599 Qualitia Active! Mail Stack-Based Buffer Overflow Vulnerability
Qualitia Active! Mail contains a stack-based buffer overflow vulnerability that allows a remote, unauthenticated attacker to execute arbitrary or trigger a denial-of-service via a specially crafted request.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 28 Apr 2025.
- Rated Critical severity (CVSS 9.8, scored by Vendor).
- It has been in the catalogue for 557 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
Active! mail 6 BuildInfo: 6.60.05008561 and earlier contains a stack-based buffer overflow vulnerability. Receiving a specially crafted request created and sent by a remote unauthenticated attacker may lead to arbitrary code execution and/or a denial-of-service (DoS) condition.
Affected Versions
| Product | Versions |
|---|---|
| QUALITIA CO., LTD. Active! mail 6 | BuildInfo: 6.60.05008561 and earlier |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Qualitia Active! Mail. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
More Exploited Qualitia Flaws
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