What’s Vulnerable › Vulnerabilities

CVE-2026-23606: GFI MailEssentials AI < 22.4 Advanced Content Filtering Rule Stored XSS

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-19 · updated 2026-06-17
• Weakness: CWE-79

Description

GFI MailEssentials AI versions prior to 22.4 contain a stored cross-site scripting vulnerability in the Advanced Content Filtering rule creation workflow. An authenticated user can supply HTML/JavaScript in the ctl00$ContentPlaceHolder1$pv1$txtRuleName parameter to /MailEssentials/pages/MailSecurity/advancedfiltering.aspx, which is stored and later rendered in the management interface, allowing script execution in the context of a logged-in user.

Affected products

• GFI Software MailEssentials AI: before 22.4 — fixed in 22.4

How to fix

Upgrade to a fixed version: GFI Software MailEssentials AI 22.4. Check the vendor advisory for mitigations.

References

• https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases
• https://www.vulncheck.com/advisories/gfi-mailessentials-ai-advanced-content-filtering-rule-stored-xss

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