CVE-2026-23621 GFI MailEssentials AI < 22.4 ListServer.IsPathExist() Absolute Directory Traversal to File Enumeration

What is CVE-2026-23621?

CVE-2026-23621 is a medium-severity path traversal vulnerability in GFI Software MailEssentials AI, published on 19 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

GFI MailEssentials AI versions prior to 22.4 contain an arbitrary directory existence enumeration vulnerability in the ListServer.IsPathExist() web method exposed at /MailEssentials/pages/MailSecurity/ListServer.aspx/IsPathExist. An authenticated user can supply an unrestricted filesystem path via the JSON key \"path\", which is URL-decoded and passed to Directory.Exists(), allowing the attacker to determine whether arbitrary directories exist on the server.

Weakness: CWE-203

Which versions are affected by CVE-2026-23621?

It affects 1 product.

Products include Gfi Mailessentials.

How do I fix CVE-2026-23621?

No fix has been published for CVE-2026-23621 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-23621 being exploited?

There is no known exploitation of CVE-2026-23621 in the wild and no public exploit code.

Other vulnerabilities in GFI Software MailEssentials AI

• CVE-2004-1312 Denial of service in n/a Critical 10.0
• CVE-2025-34491 GFI MailEssentials < 21.8 MultiNode Insecure Deserialization High 8.8
• CVE-2025-34489 GFI MailEssentials < 21.8 Local Privilege Escalation High 7.8
• CVE-2025-34490 GFI MailEssentials < 21.8 XXE Arbitrary File Read Medium 6.5
• CVE-2026-23620 GFI MailEssentials AI < 22.4 ListServer.IsDBExist() Absolute Directory Traversal to File Enumeration Medium 5.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-pcxg-vcf2-rp56.