Vulnerability record · CVE-2026-23621 · published 19 February 2026

CVE-2026-23621: Gfi mailessentials observable discrepancy vulnerability

Gfi · Mailessentials

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.

5.3 CVSS 4.0 Medium EPSS 0.25% · top 84.9% CWE-203 · Observable discrepancy

5.3CVSS 4.0 base score

0.25%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

2References

17 Jun 2026Last modified by NVD

Description

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Mailessentials Gfi

References

Link	Tags
https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases	Release Notes
https://www.vulncheck.com/advisories/gfi-mailessentials-ai-listserver-ispathexist-absolute-directory-traversal-to-file-e	Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2004-1312Gfi mailessentials vulnerabilityA bug in the HTML parser in a certain Microsoft HTML library, as used in various third party products, may allow remote attackers to cause a denial o…EPSS 2.5%3 Jan 2005 8.8CVE-2025-34491Gfi mailessentials deserialization of untrusted data vulnerabilityGFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary cod…EPSS 0.95%28 Apr 2025 7.8CVE-2025-34489Gfi mailessentials deserialization of untrusted data vulnerabilityGFI MailEssentials prior to version 21.8 is vulnerable to a local privilege escalation issue. A local attacker can escalate to NT Authority/SYSTEM by…EPSS 0.33%28 Apr 2025 6.5CVE-2025-34490Gfi mailessentials xml external entity (xxe) vulnerabilityGFI MailEssentials prior to version 21.8 is vulnerable to an XML External Entity (XXE) issue. An authenticated and remote attacker can send crafted H…EPSS 0.72%28 Apr 2025 5.3CVE-2026-23620Gfi mailessentials observable discrepancy vulnerabilityGFI MailEssentials AI versions prior to 22.4 contain an arbitrary file existence enumeration vulnerability in the ListServer.IsDBExist() web method e…EPSS 0.19%19 Feb 2026 5.1CVE-2026-23616Gfi mailessentials cross-site scripting vulnerabilityGFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Anti-Spoofing configuration page. An authenti…EPSS 0.18%19 Feb 2026 5.1CVE-2026-23617Gfi mailessentials cross-site scripting vulnerabilityGFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Spam Keyword Checking (Body) conditions inter…EPSS 0.18%19 Feb 2026 5.1CVE-2026-23618Gfi mailessentials cross-site scripting vulnerabilityGFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Spam Keyword Checking (Subject) conditions in…EPSS 0.18%19 Feb 2026

Source: NIST National Vulnerability Database (record CVE-2026-23621), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.