Vulnerability · Published Dec 9, 2025 · Assigned by VulnCheck

CVE-2025-34403MailEnable < 10.54 Reflected XSS in FieldTo Parameter of AddressBook.aspx

Medium 5.3

In plain English

A medium-severity cross-site scripting in MailEnable from MailEnable. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.4%top 66.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

MailEnable versions prior to 10.54 contain a reflected cross-site scripting (XSS) vulnerability in the FieldTo parameter of /Mondo/lang/sys/Forms/AddressBook.aspx. The FieldTo value is not properly sanitized when processed via a GET request and is reflected inside a <script> block in the JavaScript variable var fieldTo. By supplying a crafted payload that terminates the existing Finish() function, inserts attacker-controlled script, and comments out remaining code, a remote attacker can execute arbitrary JavaScript in a victim’s browser when the victim attempts to send an email. Successful exploitation can redirect victims to malicious sites, steal non-HttpOnly cookies, inject arbitrary HTML or CSS, and perform actions as the authenticated user.

Affected products (as reported)

Vendor	Product	Versions
MailEnable	MailEnable	0 – before 10.54

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

References

https://mailenable.com/Standard-ReleaseNotes.txt release-notes, patch
https://www.mailenable.com/ product
https://www.vulncheck.com/advisories/mailenable-reflected-xss-in-fieldto-parameter-of-addressbook-aspx third-party-advisory