What is the CVSS score of CVE-2026-23609?

CVE-2026-23609 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Mailessentials are affected by CVE-2026-23609?

CVE-2026-23609 presents moderate security risk, a cross-site scripting vulnerability rated CVSS 5.4. Attackers could inject scripts to steal sessions or perform actions as authenticated users.

How to fix or mitigate CVE-2026-23609?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Mailessentials CVE-2026-23609

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-02-19 disclosure@vulncheck.com

XSS Mailessentials

5.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.4 MEDIUM

AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:03 vuln.today

CVE Published

Feb 19, 2026 - 18:24 nvd

MEDIUM 5.4

DescriptionCVE.org

GFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Perimeter SMTP Servers configuration page. An authenticated user can supply HTML/JavaScript in the ctl00$ContentPlaceHolder1$pv3$txtDescription parameter to /MailEssentials/pages/MailSecurity/PerimeterSMTPServers.aspx, which is stored and later rendered in the management interface, allowing script execution in the context of a logged-in user.

AnalysisAI

GFI MailEssentials AI versions before 22.4 contain a stored cross-site scripting vulnerability in the Perimeter SMTP Servers configuration page that allows authenticated users to inject malicious scripts into the management interface. An attacker with valid credentials can execute arbitrary JavaScript in the context of other logged-in administrators by manipulating the description parameter. No patch is currently available for this vulnerability.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects the management component of Mailessentials. GFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Perimeter SMTP Servers configuration page. An authenticated user can supply HTML/JavaScript in the ctl00$ContentPlaceHolder1$pv3$txtDescription parameter to /MailEssentials/pages/MailSecurity/PerimeterSMTPServers.aspx, which is stored and later rendered in the management interface, allowing script execution in the context of a logged-in user.

RemediationAI

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.