CVE-2025-34399 MailEnable < 10.54 Reflected XSS in AddressesCc Parameter of AddressBook.aspx
Remote attackers can execute arbitrary JavaScript in victims' browsers via a reflected XSS vulnerability in the MailEnable address book interface.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-34399?
CVE-2025-34399 is a medium-severity cross-site scripting vulnerability in Mailenable Mailenable, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
MailEnable versions prior to 10.54 contain a reflected cross-site scripting (XSS) vulnerability in the AddressesCc parameter of /Mondo/lang/sys/Forms/AddressBook.aspx. The AddressesCc value is not properly sanitized when processed via a GET request and is reflected within a <script> block in the JavaScript variable var sAddrCc. By supplying a crafted payload that terminates the existing LoadCurAddresses() 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.
Weakness: CWE-79
Which versions are affected by CVE-2025-34399?
It affects 1 product.
Products include Mailenable Mailenable.
How do I fix CVE-2025-34399?
No fix has been published for CVE-2025-34399 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-34399 being exploited?
There is no known exploitation of CVE-2025-34399 in the wild and no public exploit code.
Other vulnerabilities in Mailenable Mailenable
- CVE-2015-9280 XML external entity in n/a
- CVE-2025-44148 Cross-site scripting in n/a
- CVE-2019-12924 XML external entity in n/a
- CVE-2015-9278 MailEnable before 8.60 allows Privilege Escalation because admin accounts could be created as a consequence of %0A mishandling in AUTH.TAB a
- CVE-2015-9277 Path traversal in n/a
Sources
Also known as GHSA-r98j-8f85-mgjw.