How severe is CVE-2026-23621?

CVE-2026-23621 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-23621 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23621?

CVE-2026-23621 affects Gfi Mailessentials. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23621?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-23621 have an EU (EUVD) identifier?

Yes. CVE-2026-23621 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8317.

When was CVE-2026-23621 published?

CVE-2026-23621 was published on 2026-02-19 and last updated on 2026-06-17.

CVE-2026-23621

CVE-2026-23621 is a medium-severity vulnerability in Gfi Mailessentials with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-203.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8317
Weakness: CWE-203
Affected product: Gfi Mailessentials
Published: 2026-02-19
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-23621?: 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.
How severe is CVE-2026-23621?: CVE-2026-23621 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-23621 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23621?: CVE-2026-23621 affects Gfi Mailessentials. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23621?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-23621 have an EU (EUVD) identifier?: Yes. CVE-2026-23621 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8317.
When was CVE-2026-23621 published?: CVE-2026-23621 was published on 2026-02-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gfi:mailessentials:*:*:*:*:*:*:*:*

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